Are you on stock Android? Don't know about that, but on LineageOS 18.1, in "Settings" -> "System", the last item is "Touchscreen", which lets you set (in three steps) how wide a margin should be insensitive to the touch. Personally, I'm mostly ok now after setting it to 32.
Oh, and I've reduced my drop rate (which used to be very similar to yours) to practically zero by covering the whole back cover surface (minus camera) with transparent packaging tape!