Feel the same way too. We had multiple issues with a RI, the GM promised us 20k points as compensation and he didn't follow through. So we escalated the issue to Marriott - all they did was to document everything we wrote and that is. Haven't heard a word from them since they confirmed that they documented everything. The hotel got away with giving us a suite with a non-functioning freezer (and not properly cleaned suite) and then another suite with a semi-functioning freezer for 6 nights (couldn't put ice-cream there overnight), and almost lost our ice-cream (because they misplaced it).
The messed up with my reservation with travel package 7 nights cert - so that it was changed from 2 queen to 1 king and from 5 guests to 2 guests. I called the hotel and no one answered so I called Marriott. The person said I need to go to the hotel tomorrow as he couldn't do anything. I said we were 5 people and we needed a suite that can accommodate all of us. I told him I wanted to speak with a supervisor and I got one and she sorted it out for me - but she forgot to put in my name (Mr.'s reservation). Didn't realize until check-in and it was another drama.
Marriott didn't state the limited services due to covid and we were shocked by the begging style breakfast, no extra cleaning other than the every 3rd day - again Marriott doesn't give a damn about not informing people so they can make a proper choice.
So what did we get out of this? Nothing so far.
Hilton on the other hand was much better - got a room with cracked walls and the FDC ran my debit card multiple times and couldn't cancel the reserved payment. Wrote to them and they instantly replied instead of telling me they will make a case. I heard back from both HH and the hotel within 48h and got a very satisfactory resolution.
This is HH D vs MB T.
I haven't even experienced SPG! My expectation isn't even high as I live in the land of no service Scandinavia and both Mr. and I thought Marriott was very ok!