Can someone explain why prices go up? Is it just because it’s a norm to join “good” companies?

Nvidia blah blah blah they’re incredibly profitable.

But if there was an unspoken rule, that we aren’t going to invest based off balance sheets or income statements.. wouldn’t everything be essentially a pump and dump scheme and a speculative investment?

I guess what I’m saying, is if people didn’t have an expextation that hordes would follow good fundamentals.. what is stopping public funding from drying up on the excellent companies?

Is it just because of the tradition that *good companies are attractive?*