This what Apple are good at, and largely so are most successful bodies/individuals - picking up the ball from others and running with it or, if you will, ripping off someone elses ideas...
I LOVE everything Apple, but they didn't exactly invent all of the technologies which have made them successful. They packaged them well, and they were fortunate in many cases to focus on what was popular at the time (like the consumerism shift from buying CDs to downloading music). iTunes itself was a literal repackaging of the app SoundJam MP. The Mac OS Finder derived from the ideas brewing at Xerox. Safari and many underlying OS X technologies are simply repackaged from open source projects like WebKit and Darwin's BSD core. Portable MP3 players were already selling before the iPod arrived, but Apple made it more appealing with a slick design, a decent UI, great software to match (iTunes) and larger storage capacity than the others. It was a brick, but it was awesome at the time.
The iPhone on the other hand was a great opportunity for a comfortably successful business to try something new. They had the opportunity to invent the smart phone and it was executed incredibly well.
The idea of repackaging (and culling for that matter) has served Apple well. Steve Jobs once talked about the time when he returned to Apple, he had the task of discerning between which technologies were failing and which had potential to be successful. Technically brilliant technologies like OpenDoc got axed in favor of industry standards like Java. The entire Macintosh hardware line got stripped by something like 70%. All those model numbers and product lines (7300, 8600, 9600, 5300, 1400, Newton, Pippin, etc) got the boot and replaced by the "Power Macintosh G3", "PowerBook G3" and then of course the iMac and iBook.
For me, OS9 is still a shortcut for a speedy OS on hardware that doesn't truly fit OSX. I see it in the same light as WinXP/2000/98 - it's fun to use and try and bend into modern shapes it wasn't prepared for.
Example, this week I've been trying to get Youtube playback on OS9 again - for no practical purpose of course but went down the route of VPC and ultra thin Linux distros. Didn't have any luck, there were always problems with the distro failing to recognised hardware - the most common being no mouse.
I do occasionally use Photoshop in OS9 on my TiBook but once you've got multiple layers on the go you can feel that single G4 struggling...
I like to tinker with this idea too; How to configure the most efficient system to suit the hardware. It's great to see software fly and if you have a specific task in mind, like doing layouts in Quark, designs in Illustrator 9 or 72dpi / 144dpi work in Photoshop 7, then it can be mostly enjoyable to use. Reason 2.5 and ProTools 5/FREE ran brilliantly on any G3 running OS9.
VPC (and RealPC/SoftWindows) ran far more efficiently on OS9 than in a true multitasking environment. You can squeeze substantially more performance out of it by disabling many unnecessary extensions and control panels, disabling Virtual Memory, lowering color output to Thousands or even 256, and writing a quick AppleScript which can quit the Finder on launch. All those interrupting and polling processes are gone, and the PC emulator can just run stand-alone.
Honestly I don't know how to really answer that question. There was never any middle ground for me. I saw everything about OS 9 as superior until OS X 10.3. At that point it flipped.
I didn't buy into OS X until I acquired a copy of 10.2 bundled with my G3 800Mhz iBook 12". I can vaguely recall working for weeks or months in OS X, then switching back to OS9 to perform some kind of specific task and feeling cramped in comparison. The workflows of OS9 and X were just very different, like switching between Mac and Windows. You can likely achieve the same result, but it's a different set of tools at hand to get there, so you find yourself having to choose between one or the other.
In my last office role, I had the task of administering sales and purchasing/inventory via MYOB and managing jobs/bookings via a custom MS Access database. I also had the role of designing all of the business print and marketing material and designing and maintaining the website and online store.
I would do my regular office admin role with MYOB and MS Office on a Dell tower with Windows 10 and bring in my own little MacBook Unibody '08 (with a mini-DP to HDMI adapter for the 27" display) to do all of the Photoshop, InDesign, Illustrator and web dev/prep work. I know I could have requested that the business buy a Windows version of Adobe CS, or conversely a Mac Pro and the Mac version of MYOB, but the workflow of each task was best suited (to my liking) in the way I had it.
My point is, different platforms have their strengths and weaknesses and we typically choose the easiest option to get the job done and not necessarily the most technically advanced option. Apple have followed this concept pretty well for the most part by providing "here and now" solutions to customers and not (regularly) trying to entice people to come across with announcements of amazing distant future technologies.
Peace of mind is not something that comes to me when using OS9.
I can recall many times hoping that I had enough ram left to save a file before QuarkXPress bombed on me and locked up the entire system.
Trying to make ATM (Adobe Type Manager) work and use the right fonts was a nightmare. Suitcase eventually solved that but we had a lot of calls from our printer telling us that our fonts were killing his system.
Photoshop and Illustrator handled resources pretty well though.
I agree, memory management was always an issue and it seemed to be only temporarily resolved by upgrading the Mac's RAM as projects just get bigger and bigger. Font management was painful even with Suitcase. Rarely did the classic Mac ever stay upright for more than half a day during heavy production work, especially when working on large projects. I've had a few data losses, but I conditioned myself back then to hit Cmd-S after almost every change, offload a copy to a backup hard drive regularly throughout the day (almost every coffee break) and burn off a CD or DVD at the end of day to take offsite.
It's funny, I actually still do this without even realizing. I still have a tendency to cmd-S after every change (even though modern software auto-saves EVERYTHING), Time Machine will run backups every hour and then at the end of my day's work, I zip up the current project, rename it with a date stamp and put it on a USB thumb drive so I know I have a stand-alone "physical" backup in the event of a fire or something.
Old habits (of dealing with unreliable computers) die hard.
