I’m torn about them. On the one hand they free up the combat design to be as wildly different from the exploration as it wants. Which can result in really creative stuff. Favorite examples are Undertale, MegaMan Battle Network series, and Tales series.
But on the other they interrupt the flow of exploration, the music, you forget where you were by the end of combat and they can be very annoying if they happen to be common or just as you’re about to leave an area. The consolation prize of growing stronger with every battle only helps so much.
If what’s supposed to be the core gameplay feels like an unwanted interruption, I don’t think the random enounters themselves are the problem. I think the reason random encounters get a bad rap is because some games don’t make basic fights feel engaging enough. But when done right, they should be the fun part!