Replacement batteries should be a legal requirement. My 5 year old android phone needed a new battery and people kept telling me to get a new one as the phone is old anyway. It still does what I need so why should I get a new one just because of a battery.
I ended up taking the phone apart myself and replacing it. Wasn’t easy and took me over 2 hours.
I’m up for anything which keeps phones working for longer. Such a waste of money and resources for what should be a simple job.