Notice that it does not have a headphone jack!
Only two USB C ports and the charging/dock port.
Most people who will want 5G will also use BT headphones. You don't want to be tethered to your tablet when it isn't tethered to anything else. And if you aren't tethered, then just get a USB-C hub or the Surface Hub that does have a headphone jack. If the Surface Hub is too much for you (only the really high-end users need it), I'd highly recommend getting a USB-C hub that has power pass through plus a USB charger, that way you only need one connection.
They probably merged the ARM and Intel lines so that people won't notice that they accidentally bought an ARM tablet until it is too late.
The only people who will notice are the ones who know they need an x64 (or at least a powerful processor) in the first place. x64 executables run just fine in ARM64 emulation mode. And if you do need power and know it, I'd have to question why you didn't opt for an i7, especially when you consider they are priced the same given the same memory and storage options, and the i5's are even cheaper.
And BTW, MS-Windows is still really bad in tablet mode, even after all these years. Actually, worse now in than early revisions of Windows 10 even.
I agree if you are trying to use desktop apps in tablet mode. Apps that are designed for one will always be bad at the other, and apps that try to be both will always be bad at both. That includes the window manager, but a window manager only really needs to be good enough if the other apps are doing their job. My biggest problem with using a Surface as a tablet is the bulk. It's not too heavy and the software is fine assuming you have the right software for the job, but it's just too large to hold in your hand for extended periods of time.
My issue with the SQ3 is that the ONLY incentive to get it is because you want/need 5G. You aren't saving money, and I think it's safe to assume it won't perform as well as an i7. And the longer battery life? I'll believe that when I see the test results, but even then, test results rarely match real world usage.