Octopath is fine because it's designed to feel archaic and it does it in an interesting way by rewarding you for completing those encounters with items. It's meant to be a callback to those games. Pokemon just refuses to innovate in the core series. Open world? Nah. Pokemon in the world? Sure! But only in one game. A spinoff.
When I'm trying to find me a Pikachu in the wild it gets old finding another ****ing Rattata, waiting for my Pokemon cutscene to finish, having to click run away or ko it and get minuscule exp, wait for it to load back to the overworld, walk around for another couple minutes till I get another encounter, it's another ****ing Rattata, rinse, repeat. In Let's Go, if I wanted to find a Pikachu I could just avoid the other Pokemon instead of just literally wasting time having 0 fun.
It's just dumb game design at this point and even when Dragon Quest of all things, a game that's meant to be as classic as possible, gets rid of it it's kind of ridiculous that a world wide phenomenon like Pokemon can't do it. It's just annoying.