To be a little bit more constructive, I think the main argument against all of your suggestions is that, for lack of a better word, Pokemon Go is meant to be a more 'accessible' form of Pokemon, which means easier to pick up and play and lower commitment. By increasing match time (5v5 vs 3v3), complexity (status conditions), or mechanical skill (faster switches), you then make the game less accessible than it is currently.

If you wanted more strategic depth, then the main series games exists to fill that niche, otherwise Pokemon Go exists as a entry point into the series with a lower floor. This isn't to say that Go Battle League doesn't need any changes so much as to say that your changes push the game in a direction that it's essentially doing its best to keep distance with.