Powershell 7.2 improves on 5.1?
Hmm, not so sure about that, really. It's newer, but it has some compromises due to portability. If you're setting up a new environment from scratch, then maybe go for it. If you've got a mature environment with lots of scripts then you're likely going to need and want to keep using 5.1.
Also, just using 7.2 isn't enough anyway, you do actually need to disable 5.1 in some way, at least for remote access, otherwise all you're doing is stopping using 5.1 and leaving it open for anyone who wants to use it.