Further, in some fields (biomedical) research takes so long, and top-tier journals are so selective, that a lot of work just never gets published. Slowing that process even further would wreak havoc on already way-too-long graduate careers. A really pernicious effect of some bosses who 'only publish top-tier-quality work' is many students get stuck with years-worth of negative results, and do not get to either move on or publish their work.

And that is because of the journals having limits.

I've had papers where we carefully wrote a long explanation of exactly how some feature was implemented. If papers were websites, just hide it behind a link, don't read it if you don't care.

Instead we were told to take it out as it wasted space.