The value of the physical medium is a spectrum, of course. In one direction, of course we should value reality and art. In the other direction, the threat of the "boomer stuff avalanche" is a very real problem. If you have some time, I recommend going briefly down the hole of social media channels dedicated to people dealing with inheriting massive collections of things like Precious Moments, depression glass, Franklin Mint plates, old toys, etc. Somewhere out there, someone just inherited a library of RPG books that they don't want and can't afford to move.
That being said, I've always felt that books are a part of media more worthy of collecting. Their artistic value is high, especially RPG books with interesting artwork. They can be stored in a way that is both efficient and accessible. They can be enjoyed without damaging them (vinyl - I'm looking at you). They have a track record of long term demand and value. And it's nice to think all their information will survive The Great Solar Flare.
But books still have issues. They're heavy. If not stored properly, they can deteriorate. RPG books in particular are often odd sizes that are harder to deal with. And nothing is guaranteed to hold value; even staples like antique furniture have seen their market saturated. It's nice to think that RPGs have been around enough that they will be valuable to future generations, but I'm sure the hardcore Roy Rogers collectors though that the Western was a timeless genre, too.
And personally, my boxes of Hallmark Xmas ornaments in the basement means I'm possibly not in the best position to lecture others.