I don’t think it’s blindingly obvious for most users, but there is a small amount of “friction” that’s introduced by the need for adaptors which includes both ensuring that you always have the right one when you need it, and the tiny bit of extra time and effort required to use one. For most people, that friction is so low that it doesn’t really matter overall, but for (I suspect) a significant proportion of the target group for the “Pro” MacBooks, those two things crop up frequently enough that they create a noticeable nuisance over time.
Also, that the old ports had been removed for no benefit other than aesthetics, to which other concessions to utility had also been made, was/is particularly grating to those who use(d) them frequently, so the nuisance effect has been amplified.
The return of the legacy ports is a benefit to those who use them, and costs those who don’t practically nothing, as multiport dongles and Thunderbolt docks can still be used with ease.
tl;dr: It’s not obvious unless it’s obvious to you 