I will preface by saying that someone with Lina Khan is sorely needed; Big Tech and other monopolies have gotten way too Big and seriously need to be reined in.

That said, from all the informed takes I've seen, Lina Khan was seriously... flawed (putting it charitably) in her strategy and tactics. To the extent that some observers wondered if she was deliberately sabotaging the agency just to highlight the need for new, more effective laws. She did have a novel theory of consumer harm, but that requires new legislation to enforce. Instead the way she went about it -- including by flouting due process -- was extremely counter-productive.

That was a big reason she was neither very effective in her goals (other than creating a lot of noise) nor have high political support from any side.