There are a few threads about phones here.
But we don’t have a discussion for repairable phones with a mainstream OS.
Nokia is releasing a repairable phone in the US this month.
the most interesting thing about this phone is that it’s part of HMD’s self-repair line of devices, which means you can find genuine replacement parts, repair tools, and repair guides at iFixit, allowing you to replace batteries, screens, ports, and back covers
I hope the HMD/Nokia device manages to live up to the promise. I have owned HMD devices in the past and I was not impressed.
Beyond the iFixit guides, you can also find some spare parts on Rounded.com. They are a premium spare parts reseller, so likely more expensive than eBay, but in some cases brand new.
I specifically bought my current phone because it has a 5 year warranty and promises 10 years of availability for spare parts.
There’s also the fairphone. The 5th generation is being prepared for release which could possibly get 8 years of software support.
If you’re from the US: the fairphone 4 will only be available with /e/ OS at the moment, though. Fairphone 4—the repairable, sustainable smartphone—is coming to the US | Ars Technica
Fairphone 5 with de-Googled eOS for UK.