Looking to build my first PC in 20yrs

Hi

Possibly looking to build a Gaming PC for the first time in 20 years and looking for advice on whether my build below is reasonable for the money, probably looking to run Bazzite for OS.

I want the setup for gaming mainly but also raspberry pi / Arduino tinkering, CAD as well as the usual life admin tasks.

I was / am tempted by a Steam Machine, it'll do everything I want it to - I like the SFF & living room experience offering. Is it overpriced? Yes but what isn't with AI ruining everyone's fun! Same reason I'm hesitant of building a rig, I'm somewhat offended at the prices of components since the AI rush! Anyway getting off topic...

I've tried to pick brands I'm familiar with that I know have good reliability & performance records, haven't done this for a while so possibly some spec'ing nuance I'm missing.

Appreciate any help.

https://uk.pcpartpicker.com/list/GdT4MF