Well there are a lot of thoughts going through my head.
One is there is also peak supply, whereas the combination of new hoard finds has to shrink and in fact comics grades deteriorates over time. That could offset somewhat a demand decline. Peak supply is also countered by free online scans and reprints.
You also have 2x I think the U.S. population of 70 years ago, Hollywood trend and worldwide interest, so as amazing as it may seem the larger collector base seems to still be growing the demand side.
General market conditions also seem to correlate with demand, this stock cycle seems to have driven prices for art and collectibles. On the other end of spectrum, not too many preppers building comic safe's into their SHF dried food underground stashes.
Personally, I try to maintain only around 300 GA. comics (more than Rick's 50, but less than others). There is the space and mobility (especially with slabs) and then I try to keep in my head a "what is reasonable" factor in terms of putting funds into it. Not sure I'd feel comfortable actually worrying about an Action #1 sitting around, I'd be fretting about temperature and humidity, then paranoid about break-ins.
So my buying has slowed (I think) but I've replaced it with rotating interests, upgrading in the core and balancing by selling around the "core." That keeps me engaged, but fair to to say volume-wise I've peaked (but money-wise still going up).