Advice on "locking down" my Pixel 5a and turning it into a tool? - sh.itjust.works

Hi, I’m hoping to get some help making my Pixel 5a more utility and less bullshit, but I’m not sure how to word it. In general what I’m hoping to accomplish is this: * Install a new OS to get rid of the Google crap baked into the phone. * Have a list of remaining whitelisted apps that can run on the phone at all, not just limiting permissions. I’m not sure if options like GrapheneOS have an inbuilt white list function. I’m aware that this phone isn’t security supported anymore but I want to run this thing into the god damn ground. There are a lot of posts online about Dumb Phones which I don’t think is what I’m trying to create. I want to be able to use this device as a tool, not a suck-up-all-of-my-time device. So I’d like to keep things like Camera, calls/texts, internet browsing (although I’ll have to block YouTube and such), and any other arbitrary app such as authenticators (advice on alternatives here would also be good appreciated) and advanced calculators. One of the issues I expect is that any whitelist or permissions will be quick and easy for me undo in a moment of boredom, so I’d like the process of undoing this to be slow and painful. There is a philosophy here that I believe my phone as a tool could be great, if every aspect of it wasn’t designed to waste my time and ruin my mental health. I hope I’ve explained what I’m trying to achieve well, it’s not my strong suit. Thanks for any replies, if I wasn’t clear please let me know and I’ll try and explain myself differently.