Last ditch effort. Not sure it will do anything, because it will not turn on at all. However, sometimes a little prayer and a hail mary throw does the trick.
Throw some adb commands at it while plugged into your computer. Try to get into fastboot mode to boot normally
https://droidrecovery.com/google-pixel-5a-5g-recovery-mode/
If this does not work. Your device may have shit the bed and is now bricked. You will need a new one.
While graphene os is appealing. Owning a google device, or spending the high price tag for a new one may not be. If you are in the market for a new device. I would highly recommend going with a Lineage OS compatible device. You can find a brand new one and have a degoogled experience for as little as around $100 fiat cuck bucks.
Hope this helps. Praying for you my dude.