I like the basis of this suggestion, but it's a lot easier said than done. I feel as if a lot of casual aspects of this game have been overridden by the need for balancing in the competitive scene, which is what this game has primarily evolved into ever since like 2016. It's one of the primary reasons why I don't come on as much as I used to, simply because the competitive aspect of Pokemmo has completely overtaken the casual aspect. I'm sure there's tons of players like myself, but I'm pretty certain that the developers have made up their mind as to what they want this game to be, and adding a casual mode would be a hassle. I think that new and custom minigames or quests (separate from the dungeons) should be added to the game to satisfy the casual population of this game. This seems more plausible, and I say that because the developers have been deviating more and more from the normal Pokemon games in the recent updates.
I strongly disagree with this, I can guarantee that the developers of this game intended to make the game for both casual and competitive players, but as the community evolved competitively, the game had to evolve competitively as well, and whether you like that or not, that's how it has to be. The only thing that would keep casual players around are more enjoyable casual aspects to the game being added, which unfortunately is apparently not a top priority at the moment.