Good point.Note that the Battery info in Settings does not show the extra drain people are seeing in iOS 13. That shows only app usage, not system usage, which may account for the discrepancy (i.e. it's apparently background/system processes that are draining the battery faster in iOS 13).
It's now 11:20AM. I took my iPhone XS off charge at 5:50. I'm now showing 95% charge. Seems about the same as iOS 12.
This isn't the first time there have been complaints about phones getting hot and fast discharges after a major number iOS update. It's happened to me in the past, too. Sometimes it can be fixed with a forced restart, and since that's easy to do, I would suggest trying that if you are having battery issues.
One time, around 2013, it happened to me, and I had to bite the bullet and restore as a new i-device (restoring from a backup didn't work), which stopped the discharge problem. I then re-added my apps back using some screen shots I had taken.
Given the number of apps now on my phone and the fact that one can't add them from iTunes anymore, that would be very painful.