I think the shortage of graphics chips worldwide has really crippled both MS and Sony's ability to meet demand. It'll probably continue this way for a while. There are a couple of tech sites that do follow shipping/deliveries for big box stores.
This should help for xbox. I think they also have a page for PS5.
It’s really bad. I work with electronics and we are seeing 52 week leadtimes on some chips. We are crawling out of a massive slowdown (oil and gas + Covid) where we slashed inventory for the past year. Now that we have some demand returning, we may not be able to deliver.