Have to disagree. I would say choosing the right collectibles is an acquired skill that takes a long time to develop and usually applies to a niche market, and that's why it seems like collectibles overall are a bad investment. Not only do you need to be good at estimating future value/demand, you need to be good at acquiring items for a good price + ensuring they're not fakes. If you blindly buy "collectible" items then yes, you will lose money because the "collectible" moniker is usually a cheap marketing tactic to crate the false impression of scarcity/value.

I have been buying/selling collectible video games (and related hardware/paraphernalia) for over a decade and many items are still sitting in a storage unit waiting to be listed because they continue to appreciate so quickly. My only regret is usually that I didn't buy more of each item.