As I said before, I believe that using permissive licences is a bad idea. I have seen multiple projects choosing a permissive licence as a way to compete against an already established copyleft project, just because it's easier to get adopted by companies. I find it unfair but also a bit stupid: by using a permissive licence, they allow anyone to compete with them with a proprietary fork.

Still, there is an antitrust question (that is slightly orthogonal): if TooBigTech can offer a similar product at a loss (e.g. for free) until they capture the market, then that's a problem. And they can only do it because they are too big, and that is an antitrust issue IMO.