One thing going for comics is that there will always be a nostalgia for the time before our world became digital and each individuals attention was split up into 10,000 tiny pieces, 1000's of tv channels, 10s of thousands of "social media celebrities" and millions of website. Cultural elements that come from before that tend to hold their value, as they held a greater % of the mindshare of our population as a whole.
As an example look at the incredible staying power of musicians, actors, celebrities who were at their peak during the years of 2000-2005, the years when the world went digital. They are disproportionately still global phenomenons. Why is that? The manner in which these individuals were able to hold our attention completely for 10+ years because there were only 25 channels available to us on TV, is not something that can be duplicated by tends of thousands of social media influencers all filling those same spots. People nowadays can have one of their videos go viral with 25+Million views and not even become famous. Within seconds something else has caught our attention. That is why those "super heroes of pre 90s" have so much staying power and aren't replaced anytime soon. Argument can be made that comics will increase in value for this reason, they are remnants of a cherished time.