Re: How long is the software support?
They released Android 9 for the fairphone 2 when it was 5 years old, when it was first released it ran Android 5. See https://www.theregister.com/2020/06/18/fairphone_support_comment/ I'd say it would be hard to find something better when it comes to long term software support. That's part of the ethics of the company, they strive to make their phones last long and know software is a crucial part of that. It's rather impressive what they get done being a relatively small company.
And they are relatively open towards their hardware, making it a good target for community versions too. It also runs Sailfish for example.