Wondering how to make your microphone louder on PS5? This is how you do it:
PS5 Settings > Sound > Microphone > Adjust Microphone Level > Lower / Raise the Volume
This will change how loudly other people hear you in chat. Making it too loud can result in too much background noise being picked up. Making it too quiet can make you hard to hear among other people. Try to find a setting that is comfortable for the people you play with.