I'd say the attitude of Hoenn is close, though it's not quite there beyond places like Fortree, which exude 'comfy'.
Sinnoh has its moments for sure, but it's one of the two most battle-minded regions in the world alongside Galar, plus Pokemon of Myth/Arceus aside, it's far too mountainous to call it 'comfy', especially when only Floaroma come close to the definition.
A closer one than either of the above would be Johto due to it being "Kanto's Backyard" being taken literally, as compared to the average urban nature of Kanto, not only is Johto rural by comparison besides Goldenrod and Olivine, so rural in fact the Ampharos of the latter's lighthouse needs medicine from Cianwood, aka bumfuck nowhere only traversable by boat or water Pokémon. It's quiet enough that the only real action is the Pokéathlon and the league, which it still shares with Kanto. Nice and quiet, hence anons recently commenting on the "soul" of the GBC originals.
I'd say the comfiest region by far is Alola. Not as rural as Johto besides Poni Island only having a coastal trade port and a Battle Facility even more out-of-the-way than Cianwood ever was, and until the time Elio and Selene immigrate over, there wasn't even a league, merely the local (Grand) Trials as a tradition.
It's the comfiest because it's a tropical Hawaii-based region that does not give a flying fuck about anything, not even the 'evil team' that's a bunch of hooligans that are also the best group of any kind in the series. You could settle in just about any town on the first three islands, or even Seafolk Village if you're daring enough, and you'd be more than fine for the rest of your life.
