The S22 is a good phone in my books, this is coming from someone who has been using it for a while. Sure, it may get warm and you may need to top up the battery, but other than that you should be fine.
The battery will only last the whole day depending on how you use your phone. Streaming music in the background, doom scrolling, etc, will drain your battery.
If you could, get the S23 instead. But if the S22 is a good deal compared to a S23, you’ll be fine.
I’d say save your money and get an S23. From what I’ve heard, the battery life on those things are fantastic. You may not see much of an upgrade coming from an S21, but it’ll last you in the long run as long as you don’t crack it ;)