Yes and no. For example, I work in pest control and mostly lurked twitter for pest control content, as a lot of experts in that field used twitter exclusively and never bothered with facebook, instagram, reddit, discord, or any other networking site.

There is absolutely no pest control content from those experts on Mastodon at this time. Niche, I know, but its a concrete example about how not every base is covered on Mastodon (yet).

Its silly to blame people for not flocking there when there is a demonstrable lack of content.