I have a Samsung Note 20 5G that drains a lot of battery because of social media apps such as WeChat that constantly checking for new messages/notifications -> 700MB+ size apps that doesn't make sense to me. I can't uninstall it because need to communicate with relatives because they said they only use wechat often than whatsapp, and I hate it.

What you need to do is uninstall Facebook, it's one of the culprits that drains your battery phone.

I don't know much about Vivo but if it's Samsung, if the apps didn't open for some days it will turn from inactive to sleep mode.

but if it's every other day use apps you check back which apps are draining your phone if there are any, other than hotspot like you had mentioned, or get a 2nd phone to turn it as hotspot phone instead