One issue is that the current gatekeepers (peer reviewers for journals, grant proposal scoring committees, promotion committees, etc.) are often the people most prominent in their field. On one hand this makes sense for obvious reasons (an expert is the most equipped to judge their field), but on the other hand things like the amyloid hypothesis get 'baked-in' because, well, it's pretty hard to ask those same individuals to highly rank a large grant proposal that goes against their own theory.
So I think the answer is gatekeeping needs to be different -- not less.
Do note that the more the gate is kept, the stronger the incentive for cheating. Moreover, peer review is overrated.
An experiment by the NIPS conference in 2014 found that ~60% of submissions are in the "gray middle" - not obviously great or obviously crap.
In more detail: they split the PC in two, and had 10% of papers (166) reviewed by both halves. Each half had to accept ~37 papers. The halves disagreed on 21 accepted papers [1].
So yeah, if your submission is sciencey, it's the flip of a coin whether peer review will accept it.
So I think the answer is gatekeeping needs to be different -- not less.