Don't buy a new phone, just repair it.
Context: Day one S23 Ultra heavy user.
Last week I noticed my phone would turn off after reaching ~30% and would lose charge overnight.
Since I always use a case I didn't notice until now: when I removed the case, the back of the phone was peeling off due to the battery being swollen. Honestly didn't want to throw the phone away, it's still buttery smooth and in almost perfect condition.
Looked around and decided to give it a shot at changing the battery myself. I wanted initially to buy one off Amazon but I didn't personally trust it (despite having zero experience with battery replacement), I saw some people suggesting to buy it from ifixit.
50€, arrived yesterday, replacement wasn't that hard honestly, majorly thanks to the battery having a pull instead of being filled with glue and the glue of the back being already removed for most part by the swollen battery.
So far so good and nothing broke, phone feel like new, lost 0% overnight. Will have to see how its going after a month though because I saw some negative reviews about it, will comment an update in about a month.
Edit: grammar.