As someone who has gigabit, basically the only service that can reliably saturate that is Steam.
Realistically, the right math to do is a ‘how many people are here, and how many 4k streams are going to be watched at once, and how many megabits is that’ since almost nothing else you do is likely to do a sustained saturated use of your throughput for most (read: non-super-nerdy types) people.
Also if you have to ask, then you’ve never noticed and are in that ‘don’t really care’ zone, and you can probably get whatever you want and be fine.
Lol, they’re just renaming Remote Desktop to Windows.
So I can use Windows to connect to Windows, and run my Windows.
Truly a moment of marketing brilliance.