The only Pixel I have is a Pixel 3XL which is not supported anymore for updates. A few questions. does that mean at some point you have to buy a new phone all the time? How long are they supported, do I need the buy the newest one everytime to have a decently long support? If I can install Calyx, but have already degoogled my phone, is Calyx still useful? But I suppose at this point it’s still better to get a Pixel anyway and install Graphene which is supposedly better? how risky is it to run an unsupported phone like my Pixel 3XL? What can happen?
Yes and no. There are new security vulnerabilities discovered every day and if you aren’t getting security updates your device will not be secure.
If you spend a couple hundred bucks you can get a Pixel 8 and it will be good for another 5 years.