Other than your carrier give it for free or cheap, I don’t really see the reason why should you buy new phone. I’ve been using Redmi Note 9 for past 3 years and recently got my had on Poco F5. I don’t see the point of my ‘upgrade’. I sold it and come back to my Note 9. Gaming? Most of them are p2w or microtransaction garbage or just gimped version of its PC/Console counterpart. I mean, $400 still get you PS4, TV and Switch if you don’t mind buying used. At least here where I live. Storage? Dude, newer phone wont even let you have SD Card. Features? Well, all I see is newer phones take more features than it adds. Headphone jack, more ads, and repairability are to name a few. Battery? Just replace them. However, my Note 9 still get through day with one 80% charge in the dawn. Which takes 1 hour.
I am genuinely curious why newer phone always selling like hot cakes. Since there’s virtually no difference between 4gb of RAM and 12gb of RAM, or 12mp camera and 100mp camera on phone.
I have been using my poco f1 for more than 4 years now, the only problem i have had is the battery. It has an sdcard slot, headphone jack, 6gb of ram which has been more than enough and latest lineageos is supported. see https://fsfe.org/activities/upcyclingandroid/index.en.html