I'm not really sold on him either but here the thing...
For one, if we get him for £35m at age 24 (his current age) we can sell him for £25-30m at age 26-27 and basically recoup most of the money. In the meantime we avoid having to play McTominay or Fred at DM which we have to agree are just not as good. Or, god forbid, Matic.
The other thing is, we've been talking about this all summer and no one has actually come up with a ball-playing DM that is better. Bissouma, Tchouameni are more athletic for sure, but they are not better passers than Neves. Camavinga is a box-to-box really and he is also very young and likely to be one for the future rather than one to improve us immediately.
Players like Jorginho, Locatelli (just moved), Fabinho, Veratti... just aren't available. There's a dearth of good ball-playing DMs. So if we want to go for a Carrick-esque player and it's not Neves, then who?