[jhrmnn]

I (not OP) do, https://jan.hermann.name/publications/ (note the copyright notices, required by the journals, which pop up when you hover of the pdf link [didn't figure out a good alternative on mobile]). In rare cases, the journals don't allow this at all, in some cases they allow you to self-publish only the submitted manuscript, before any modifications based on peer review.

As for why it's not enough—because hiring committees and funding agencies almost never take unpublished (that is, in a proper journal) manuscripts into account when evaluating you and your funding proposals. This is what needs to change in the first place to break the loop.