I've been hearing that comic book collecting is dead, and that the hobby will go the way of stamp collecting, for DECADES. No, it won't. Comic books are too cool. With James Gunn (proven track record) running the DCU unit of WB, a lot of excitement in DC films is on the horizon. And then Marvel Studios -- in the middle of a course correction after realizing their frolic-and-detour of 2021 to 2023 cost them literally hundreds of millions of dollars in lost box office revenue and eroded viewer (and comic book collector) goodwill -- will bring out new A-listers from the Fantastic Four and X-Men universes. That will generate even more excitement on the Marvel side.
To the OP, if you don't need the money today, but want to liquidate, consider selling your collection in increments spread out over a five- or 10-year period. It's impossible to time any market, but this way you can hedge some risk while also realizing potential reward with market upswings for Marvel books that, i honestly believe, will come in 2025/2026. Since your portfolio is concentrated in Marvels, you're better off waiting a bit rather than unloading it all now in a soft Marvel market today.