It seems that each year, Marriott has devalued the value of their points. I found an article by Gary Leff on View from The Wing that goes into detail on the latest point reduction. Thankfully, there are people who go through these analyzes because Marriott is no longer providing its member this information.
Gary Leff laid out the price change by Hotel Category
| Category | Min/Night (1st half of 2025) | Max/Night (1st half of 2025) | Max/Night (2nd half of 2024) | Change on Cap % | ||||
| 1 | 5,000 | 18,000 | 16,000 | 12.50% | ||||
| 2 | 10,000 | 28,000 | 25,000 | 12% | ||||
| 3 | 15,000 | 36,500 | 36,500 | 0% | ||||
| 4 | 23,000 | 55,000 | 50,000 | 10% | ||||
| 5 | 35,000 | 76,000 | 69,000 | ~10% | ||||
| 6 | 40,000 | 88,000 | 84,000 | ~4.7% | ||||
| 7 | 50,000 | 105,000 | 102,000 | ~2.9% | ||||
| 8 | 52,000 | 140,000 | 130,000 | ~7.7% | ||||
| 9 | 88,000 | 152,000 | 132,000 | ~15% |
It is amazing how much the value of the Bonvoy points have been compressed over time. A quick look back from 2020, if you look at the highest rate for a category 8 hotel, shows a reduction in value of 40%.
Prior to these changes, Nerd Wallet calculated Bonvoy points as being worth $.09. I wonder how that will change. Nerd Wallet continues by saying that the Marriott Bonvoy points are below average for the hotel category.
With all this data, I do not know whether it makes sense to store up your Marriott Bonvoy points since they get compressed over time. My suggestion is to use them as you accumulate them.