Yes. The NIH intermural study on ME/CFS took well over a year to get published.
The sheer volume of papers on Covid/Long Covid et el is staggering too something like 3/4s of a million individual bits of research have been published (all showing its bad news for humans!) and that combined with the doubling of days out sick everyone is enduring due to multiple Covid infections and the brain fog from Long Covid is likely not helping to get things handled quickly.
These analogies don't work. Sending a bunch of data to a computer and receiving a bunch of data in return is in no way analogous to physically entering private property without permission. They are not the same thing, or the same order of thing, or at all comparable.
The only "real" thing about either of those 2 cases is social conventions.
Is is entirely impossible to imagine a culture where walking unbidden into private property is very normal but pinging someone electronically without a common understanding is an intrusion?
Beyond the TOS nobody reads (not even sellers), this sort of difference might be due to a number of factors. It could well be that they provide rooms discounted to Booking.com because they want to fill a certain amount no matter what, and then do price-anchoring for other rooms on their website. This is more or less like them giving rooms massively discounted to package sellers (Thomas Cook etc).
Is it normal that it takes so long to go from Received to Accepted?