The trend is towards consolidation. Nobody carries a dumb phone plus stand-alone GPS anymore when a smartphone with Google Maps is a superior single device solution. Same reason iPad plus Macbook is obsolete since iPad can only run blown up phone apps and Macbook lacks pen and touch inputs. There's no reason Apple can't make a comparable Surface Pro device running MacOS other than greed with making you buy two turkeys. Apple will eventually give in like reversing its stance on phablet, stylus, etc. but 4 to 5 years behind the competition.
Um, no. It's a UX thing. A tablet isn't a laptop and vice versa. This isn't because of hardware capabilities, but usability. I often carry an iPad and MBA when I travel, as the iPad is pretty good most of the time, or while on flights. But, when I have to do more complex work or dig into a more serious customer problem, I need the laptop. (And, no, a Surface wouldn't cut it... nor some kind of kludgy iPad-MacBook thing.)
BTW, Apple didn't reverse any stance there. The Apple pencil isn't a stylus. Again, it's a UX thing.
And, the day Apple puts a touch-screen on a laptop... well, I'm afraid to say it, because the 'new' (stupid) Apple just might do something that daft.
BTW, I used to be a full on windows guy until I tried the Mac ecosystem last year for the first time (mac computer, iphone and an ipad). With features like Continuity (microsoft has nothing like this) and the fact that nobody makes apps for the windows phone, going full apple ecosystem is a no brainier.
Welcome... though I wish you could have seen Apple at it's peak. Aside from Continuity, OS X has been mostly a downhill trend in usability in the last several years.

I actually fear I might need to go the other direction one of these days (or to some 3rd option).
There's nothing to compare to with the iPP. iPP doesn't even have a file system, meaningful multitasking or ports. The SP4 is so far beyond the iPP all they can do is go after that MB line.
I'll give you that. It would be *much* more useful if it had a reasonable file-system. The kind of multitasking you're talking about is desktop OS though. But, the SP4 is a kludge.
I love macs and APPle but someone at the top made some bad decisions from 2013 to now.
To make computers with 5400rpm drives, old processors and no ram at the prices they're asking AND
to make them non upgradeable...BAD Idea!
How much money did they make from having a 16 gig iPhone vs the bad ju ju they got from It?
These bad decisions are showing up now in the Apples sales and stock price.
So unless they change their course..I'll buy used macs.
This is what happens when you switch from UX being top priority, to spreadsheets, pie-charts, marketing, tech-industry CEOs, etc. being in charge. Short-term thinking run amok.