Fast charging is a factor to battery degradation but not by a sizeable amount. Using a 20w charger , currently I'm at 100% after 7+ months.  Bought on November.

I just practice the 30-80% rule and so far it seems to be working . The 'usable' 50% battery is enough to last an entire day for me , so yeah I don't mind it.

Anyways if you don't care just use the battery as intended , 93% after 6 months is still okay and decent. The reason I'm keeping it this way is that i can sell it when i upgrade to the 13PM or wtv the next iteration is.

Even 30w should be fine since it'll just fix the charge rate at 20w

This is my first time using an iPhone since the 3gs, wanted to try it out first to see whether I like ios or not. Didn't really want to get the 12 PM since I was afraid I wouldn't like it.

After using it for a while, I absolutely love ios even bought the AW lol. So yeah I want to upgrade to the 13PM as soon as it comes out as I'm done 'testing'.

Aiyo, 98% after 8 months considered very good already la, hahaha...

You can try to backup, factory reset and restore - it could possible go back up to 99%