Or you could just join me and be in denial of it.

I'm only half joking. I think it's notable that chess players tend to peak in their mid to late thirties. But that's only looking at world class players who have reached something relatively close to their genetic potential for the understanding we have today. It's entirely possible for 'regular' humans to continue seeing major improvement well past 40. I know that some players have achieved the GM title in their 50s and 60s. These were already strong players beforehand, but maintaining the level of play to get those norms and ratings is a very significant task for anybody.

It's entirely possible that these observations are 100% consistent with the reported observations and analyses, but if so then those analyses don't really matter in the way that we intuitively think they'd matter.