S24+ or S25+

I'm looking for a phone for my father. He doesn't game or do anything that would push the phone, so CPU performance is not important. Software support, battery, and camera are the key factors. He will use the phone for up to 5+ years, so long software support is essential. I'm recommending the S24+, while he thinks the S25+ is better (“bigger number = better,” I guess). They both share the same camera, screen, and battery. The only differences are the CPU and 1 extra year of support but the price difference is huge. $880 for the S24+ vs $1,400 for the S25+ (taxes are great, aren’t they?). There’s also the S24 Ultra at $1,050, but he thinks it’s too bulky and feels like a brick. Which one makes more sense? How is the battery life on these devices and how long will Samsung support them?