I think I have pretty good evidence of the well known sabotage.
I got my S10+ on 17th July 2019. Four months pass - exactly four months - I had a software update on the 17th November. Up until this update, my phone lasted 48 hours on battery. The second I got this update, my phone now lasts 24 hours on battery.
This is how and why a brand new phone lasts 3 years before it is useless... A sabotage 'staging' process. This is disgusting when you spend over £900 on a phone (double what my laptop cost me!) and it's lifespan is being controlled in this way to force the consumer into purchasing a new phone every three years!!!
Factory reset your phone, choose the fresh start option during setup instead of restoring from a Google Cloud Backup and odds are your battery drain probably will go away.
If you don't take care of the battery (only charge between 40% and 80% and never charge overnight) then that could degrade after 1 year but any decent phone repair shop can put in a new battery for a fraction of the cost of a new phone.
My wife has a s9 for 2 years and kept it in a otterbox. The day befor Thanksgiving she plugged it in with a Samsung charger and the phone shut off. When we tried to turn it back on the battery was dead won't charge. We have never had any issue with it. Took it to replace the battery and nothing. Went back to verison and they said we need a new phone. We just played off her phone and now its trash. We may never buy another samsung again