Standard cosmology is a consensus based on interpretations of spotty data and imperfect methods, therefore standard cosmology itself is a bit "fringe". It natural given the context. Alternatives to standard cosmology will also be "fringy" for the same reasons, and possibly more reasons too.
Dismissing all alternatives to standard cosmology as "fringe" is not helpful when standard cosmonlogy itself is "fringe".
Granted, there will be really far out there alt theories. The uncertainty of the context will bring out wild hypotheses. Figuring out who's a charlatan and who is in the ballpark can be difficult under these circumstances, but we have to.
The vast majority of “fringe” stuff comes from people who don’t really understand the standard model or modern consensus. It consists of half-baked ideas that don’t hold up to passing scrutiny by those who understand the field. Not because of any bias… but because the ideas have glaring flaws, don’t explain existing observations well, or are mostly incoherent.
Science is hard, and it takes a lot of work.
I’m guessing this is what the parent comment was referencing.
The problem is all the easy problems have been solved, and even all the hard problems have been solved in science. We're down to the really hard problems, and since our otherwise astoundingly accurate observations of how the universe acts are thrown off by them, everything looks weird and fringe at the very hard edges.
Sure, we have to think outside the box to solve some of those problems. Or we need more data (and tech to gather it with). Or both. Thinking outside the box means differing from the standard consensus. Differing from the standard consensus causes controversy. Some wildly outside the box thinking will be not even wrong.
Dismissing all alternatives to standard cosmology as "fringe" is not helpful when standard cosmonlogy itself is "fringe".
Granted, there will be really far out there alt theories. The uncertainty of the context will bring out wild hypotheses. Figuring out who's a charlatan and who is in the ballpark can be difficult under these circumstances, but we have to.