I dunno, I am pretty sure I got Java readability the second month I was at Google and was already in the OWNERS file.
I was a readability reviewer and most of the readability CLs were the first project a person worked on at Google, often rather unnecessary but redone strictly to meet readability requirements (largely new code, more than X lines, etc.). I would go back and forth for quite a while to turn 1000 careless lines of throwaway code into 50 lines that were actually good, but I basically had to grant readability after that one interaction, and it never felt great to me.
The most hated readability process at Google was Go's process (at least in the early days; k8s is obviously not using it), but I think it was actually one of the best. It took me a long time to get Go readability, but after going through the process I feel like I'd write the same Go code as anyone on the Go team. When I look at people's open source projects I think to myself "don't they know that that Simply Isn't Done?" But of course they don't; Go readability can only be experienced, not explained. People didn't like that process, and I am sure I said nasty things about it at the time, but in retrospect I really like it.