>>26652786An Evil team has a reason to be doing what they do. It may be a weak reason, but it is still a coherent one.
It also provides for a flow of baddies to sneakily increase the level of the next gym, and by extension, everything.
Individual baddies have a certain risk of turning out like Zinnia. Show up out of bum-fuck nowhere, crazy around for a few hours and shit every where, then disappear into the night once they are done. They don't HAVE to turn out this way, but we all know GF.
What's more, there would be little sense of progress. You've beaten Babyfarts Mcgeezax, but that has absolutely no bearing on what Billy the Kidd is doing in the next town. You don't feel like you are getting anywhere.
The Zinnia concern is the bigger one. GF has a hard enough time writing for one villain. Trying to get them to write for five is certain to result in the character Sinistro, who introduces himself as a bad man who is mean to his pokemon before stealing the rock of the lake, and camping out in a cave until you beat him and his team of Zubat, Grimer, and regional rodent causing him to lament.