Go to Developer settings, Go to Running Services, Check which are running in background without your permission/Knowledge and Then Go to Normal Settings app/Apps, from three dots options, enable/show system apps, then go to required app name, then Disable/Uninstall..
next Disable Auto Sync from Notification/Quick panel, sync it manually if u want
Dont Use Airtel sim, It takes more battery to get signal, use jio, select LTE mode in Normal time, use 5G in your required time.
Use single sim if possibl, y bcaz, Samsung is not that much optimized for 2 sims may be..
