I checked out of a Marriott hotel Friday and today is Sunday and points haven’t posted yet. Oddly, if I take an uber and get points, they arrive within hours. Starwood used to post most stays by the next day, which makes sense since they often do it in a nightly process, but why is it usually taking about 3-4 days for Marriott to post a stay? This delays access to the points as well as a new elite level one may be reaching.

Officially you have to wait 10 business days as some stays especially those booked under corporate or convention blocks can take the whole time. Usually most of my stays post 2 days after checkout. Unfortunately, this hasn't been starwood in about a decade.

mine seem to take 3-5 days

My "usual" experience is also as noted above, i.e. 2 days for stays to post (for the record, IHG also takes as much, Hilton normally posts in 1 day). When you go to submit a missing stay request online, it tells you it "may" take "up to" 10 business days after checking out for stays to post, but this is not hardcoded in the form (i.e. you can submit a claim also earlier, just remember you must have and attach a copy of your invoice). If you are in a rush, you would be better off contacting the hotel directly first, to make sure they have forwarded the stay data to Bonvoy (I have had cases where missing stays were credited a couple of hours after contacting the hotels).

Most of the time it posts two days later for me, but if it hasn't posted by three days after I usually don't get the points or night credit unless I contact Marriott (which you have to wait 10 days to do).

3 days minimum. Often longer over a weekend.
Not sure what the relevance is.

Could Marriott post faster? Obviously. Do they? No.

In the US - 3 days

Anywhere else - Next day after checkout

YMMV…

In my experienc 85% next day, 10% after 2 days, 5% after 3 days. If it hasn’t posted after 3 days, it’s not happening without a manual request.

99% of the time it's 2 days for us.

Usually 2 - 3 days, sometimes 4 - 5.

I don't worry about it though as I'm rarely waiting for the points to turn around and use them immediately.

Out of probably 400 stays over the past 5 years I've probably had 1 where I had to make a request for the points/nights so I don't pay too much attention as the system seems to work and even if there's a couple day delay they eventually post.

My experience is generally 2 business days.

Marriott takes the longest out of all the chains in my experience. Hilton is the quickest - once I got my points the same day as checkout! (but that's not the normal)... but their normal is early morning the next day. Hyatt is always early afternoon next day. IHG is early morning second day. Marriott seems to be mid-day on the 3rd day for most of my stays, which seems quite slow!

For me it is usually the next day. However, the app doesn't seem to refresh properly. Resulting in showing the points for a stay but not the nights or vice versa. Sometimes I really need to log out and log in again for it to force a refresh. My rule is: If it the points are not posted 3 days later then I file a claim. Based on my experience if there not they are not there then then they won't ever be posted.

I’m wondering why it takes so long for the points to be posted, or why they are sometimes incorrect. I would have expected it to be a completely automated process without any manual interaction.

Your expectation does not reflect the reality of the process flow or the fact that the Marriott Points System and the Hotel Systems are not integrated to allow what you suggest. Sadly, there are people involved, lots of different property management systems, and different processes at different properties that make this a far from seamless exercise.

Now that said, I have no idea why this points posting timeline is such an issue for so many people, or is it just an issue for FT-ers looking for something to complain about on the internet?

I for one am not sitting on my Bonvoy Points account 24/7 like I'm hatching an egg. I will do a periodic check-in to make sure all my stays have posted and write in if required, but I don't need immediate gratification nor do I wind up with severe anxiety of my points aren't posted within 3 days of my stay, cursing out the criminals at Marriott and railing on about how I've been "Bonvoyed" again.

I can understand particular situations where one might be needing points from one stay to book another, but I would think those cases are fewer and further between than the amount of complaining about slow posting would suggest.

My advice to all: It is what it is, accept it as you can't change it, no matter how many posts you make about it on FT.