Anything manufactured and sold and marketed and purchased as a collectible can’t become a collectible. It’s only after the product is no longer produced, and people still want the product, but there is a limited supply of the product, will the value of the surviving instances increase.
Comic books from the 80s are generally not collectible, because everyone who bought comics in the 80s kept them, and so there are thousands of copies out there. Only a few issues are collectible, and those are ones where the print run of the original issue was a lot smaller than the subsequent interest in that particular issue. There are all sorts of issues of comics that have the first appearance of some dumb character that no one cares about. But if you have the first appearance of a particular character that is popular today then that issue is potentially valuable, simply because the publisher didn’t know to print an extra million copies of the first appearance of Wallaby Lass. If they knew Wallaby Lass was going to sell an extra million copies they would have printed those millions, and so the Wallaby Lass issue wouldn’t be worth anything special because anyone who wanted it could find an issue lying around.
And so with beanie babies. The factory that made them could make as many as they wanted, the scarcity and thus the secondary market was entirely artificial. And so there is no secondary market today for beanie babies, except for a very few rare specimens that nobody has. So “having lots of beanie babies” is a thing, but “collecting beanie babies” is not a thing.