I currently have s21 ultra and s25 ultra is about to launch. I was researching online until what year will the s21 ultra keep getting updates (2026 or 2027) after i have received the android 15 (this phone has supoort for 4 OS and 5 yrs security patch). I do feel some jitters, animations break out while daily usage and battery is not in good condition ($100 for new battery) but it can run for 2 more years if it will get updates. So I am confused wether should I upgrade to S25 ultra or upgrade its battery and run it for 2 more years.
