I don't think this is realistic. I'm a good programmer, and it speeds up my work a lot, from "make sense of this 10 repo project I haven't worked on recently" to "for this next step I need a vpn multiplexer written in a language I don't use" to, yeah, "this 10k line patch lets me see parts of design space we never could have explored before." I think it's all about understanding the blast radius. Sonetimes a lot of code is helpful, sometimes more like a lot of help proving a fact about one line of code.
Like Simon says, if I'm driving by someone else's project, I don't send the generated pull request, I just file the bug report / repro that would generate it.