There's lineageOS for outdated pixel device, but I think you loose device attestation if you flash that, so your banking, payment and digital-ID apps won't work anymore which is kind of important features for a lot of people.
I still think separating a phone for phone apps and a PC for productivity, is the best choice even if that PC is a 20 year old rustbucket from the dumpster, it will still do more tasks than a phone. You can't learn photoshop on a phone.
The lineageOS kernel isn't guaranteed to be super up to date. It's often based on the manufacturer's kernel. There's also possibly binary blobs involved which can't be checked or updated.
There is a growing trend among banks to keep the web app usable only for emergency purposes (notify bank that your phone got stolen or lost and authorize the installation of the bank on a new phone) and only allow functionality on their mobile apps.
I've seen that claim around, but I have yet to see a bank claim to have this obviously unworkable policy, or to see someone identify a bank that does have it.
I haven't seen any web apps that seem to be intentionally unusable, or any belonging to banks, personally at least. I don't think anybody is doing this as a publicly announced policy. But I have seen several websites for major institutions with major features totally unusable on their website, that should be found in a matter of minutes if they had even one QA person actually trying to use the website after updates. It's not announced, but it's hard to imagine it's not intentional.
For my most recent personal example, go onto State Farm's website and try to create an account. Goes to a blank page. It only seems to work right on their mobile app.
"work pc" -- random 50 dollar fire hazard running Linux. Anyway, those Android phones though they are obviously going to be the unreliable part in this story.
I'm right there with relating to this mindset, however, I recently (in the past 2 weeks) got to experience restoring a new phone from backup without the old one present, and it's becoming essentially a non-issue. I can't think of a single thing that wasn't restored from cloud backup.
Sure but at around 300 bucks is still way over 50 bucks.
And even if you get a used Pixel 8, having separate phone and computer adds a priceless layer of redundancy and flexibility.
If someone steals my phone, I don't want to also loose my work PC with it.