I feel so dumb.
I have over 300 hours in the game and just realized yesterday that all of my paladin builds feel like trash because you need to turn non-crit smites on manually.
I kept wondering how people were getting such good damage numbers consistently and finally noticed someone manually turning on smites in a build video.
The hype around paladins makes so much more sense now, and I feel like a whole new world of opportunities has been opened to me, but damn do I feel dense for not realizing sooner.
Edit: not only can you manually click smite, but you can also set up the game to ask you if you want to divine smite everytime you attack with a standard attack, that option is in the reactions tab and is on by default for crits (without asking) and turned off by default for normal attacks.