Since I switched just a month or two ago yesterday was flakes-figuring-out-day for me. It's terrible in the sense, that the first thing I had to do was actually figure out what flakes even do and what is it you can use them for. The guides didn't help a lot because they assumed I alreary knew that. I think I understand now, but there is an offchance I got it compeletly wrong and that bothers me.
To be fair... Flakes are still marked as an experimental feature, so they are telling you it probably won't be documented and the interface could change. But yes, given how widely adopted they are in the community, it's definitely time to document them better and ideally make it the default for new setups.