Could be the battery. My 5a5g died after 3 years and it was the battery. I couldn't get it to boot that I could tell even while charging. Didn't try calling it though to see if it rings.
Sounds odd, but have had similar issues with a Nest cam. Main powered doorbell camera resets when someone rings it until I replaced the battery.
Can't remember if the 5a5g had a headphone jack (using 7 pro now), but you can kiss that goodbye. Fingerprint reader is in the screen now instead of the rear, but otherwise its been functionally similar.
The 8 line has extended support. If you care about security updates I'd check https://endoflife.date/pixel and pick what's affordable. (a) models are at the lowest end, followed by the regular 8/9, then pro models for the best hardware.
Graphene also recently added some options like:
- Cap charging to 80% to extend battery life.
- Fingerprint reader + 4-6 digit pin. My normal pin is long so I'm happy with this change as forcing my biometrics won't unlock it alone. Capped at 5 attempts.
- Kill switch pin. If forced to give up a pin it will factory wipe the phone.