I have a 4-year-old Samsung S3 Mini. I keep wi-fi, bluetooth, data, GPS turned off by default, make few calls, don't send or receive many texts, and if I don't

I have a 4-year-old Samsung S3 Mini. I keep wi-fi, bluetooth, data, GPS turned off by default, make few calls, don't send or receive many texts, and if I don't use wi-fi or play games the battery will last several days - probably 5-6 days when the battery was new and now a bit less. However, I do usually turn wi-fi on for 10-20 minutes a day (e.g. look at HN and follow links to a few different news articles - news sites can be quite processor-intensive) and that knocks at least a day off the battery life. If I play a game, even fairly simple puzzle games, I need to charge it that day. I'm also on my third battery for it as the previous two eventually got to the point where they couldn't hold a charge at all, so I'm very reluctant to upgrade it to a model without replaceable battery, but alas, that leaves few options. I'd also like a new phone to fit in my pocket like the S3 mini does, and as far as I've seen those two criteria knock out every recent-gen phone. I can only hope that sooner or later a company decides people like me are a big enough market segment to reach out for again, but I suppose people who are happy to keep a phone for 4 years are not good enough customers and need to be forced to buy a new phone every year by the battery dying.