I set my iPhone 15 Pro to 80% i use WiFi in home make few phone calls, after around 25 hours since being charged to 80% my phone is 73%. i won't recharge phone till 2pm today battery shows normal.
I notice no heat in pocket or while it is charged, geting phone back to 80% takes maybe 20 minuets.
I am thinking your Aps might be using your battery, try setting them to only when in use.