There really is no excuse for why Apple solders their new drives (when they make plug-in replaceable PCI bus drives). They do it for sheer GREED reasons (They don't want you buying a 128GB version and then replacing it with a 2TB drive for under $300. They want you to pay $1400 more so they can pocket $1100 in pure PROFIT. That is the problem with Apple (worse than ever today; it wasn't so bad in back in 2008, for example let alone when they made a beautiful Power Mac that had a side latch where you could put in PCI cards without even needing a screwdriver to open the case). They treat Mac users as morons who don't know how to plug in a connector and are willing to buy a Mac anyway, even if they're blatantly ripped off.
I just upgraded my 2012 Mac Mini to 2TB SSD and 16GB of ram for a total of $300 and it feels like new again. My alternative to get the SAME SETUP was to spend $2700 for the new Mac Mini. Other than a somewhat faster CPU and built-in GPU (you have to buy a Thunderbolt 3 external GPU if you want anything remotely approaching gaming capability on it, even for just Windows and that would put you well over $3000, which is RIDICULOUS. There isn't ONE Mac that can compete with a $1200 Windows custom built tower for things like gaming. You have to pay over $3000 to even get close. Don't get me started on the new Mac Pro. It's priced completely out of the consumer price range. Well, that's not to whom it's targeted someone might say. Yes, but there is NO other upgradeable Mac out there today PERIOD. Cannibalism of sales? They don't offer ANY 'power' consumer Mac so what's to cannibalize? Sell the TOY computers to the fanboys and let the real hobbyists have a real computer already!
I just put Windows 10 on the 2012 Mac (I bought Windows 8.1 Pro on sale for like $68 many moons ago to play a certain pinball game (along with many other old PC games) in Windows, only to discover my RAID 0 setup couldn't have more than one boot partition so it sat there unused for years). Now with the SSD, I can put Boot Camp in there. I found out you can use a Windows 8 key for Windows 10 straight up. So I got Windows 10 Pro for $68, essentially. I have to say it's not "awful" so far. It boots even faster than Mojave (about 15 seconds compared to 23). All the old games I've tried have worked so far. That pinball games works. With MacDrive installed so Windows can read HFS+ and even APFS now, I can even run KODI on other devices in other rooms in the house and it can access my media library from Windows or macOS. The next version of macOS won't support my old Photoshop CS3 anymore or Office 2008 (32-bit software) along with most of my Mac games which would stop working as well. Meanwhile, Microsoft Office 2000 and Photoshop 7 STILL WORK from my old pre-Mac machine in Windows 10. Apple is meanwhile heading to oblivion (nothing like killing off the few games ever made for the Mac in one fell swoop by dumping 32-bit support for highly questionable reasons and almost no real benefit to the user). Apple's problem has always been less software support and now between dumping older programs that won't get updated (like games) and shoving Notarization in everyone's face in the future, it will bring the Mac back to PowerPC days support levels....
No wonder Jony Ives left.... It's no longer about state-of-the-art hardware and tools to enable users to do great things, it's about the next quarter and stock buybacks and profit margins and that's about it. It's quite sad. Apple wasn't cheap under Jobs, but it wasn't just a money making machine either. It attempted to make truly great products. My 2008 Macbook Pro was rated better than the others of the same type running Windows and a good value. The 2012 Mini Server was a good value. The new Mini is a model of fleecing with no other alternatives for Apple's RIDICULOUSLY OVERPRICED DRIVES than to buy the smallest one offered and go external afterwards (making a mess of the desk that a small footprint computer was supposed to cleanup).