Maybe some people behave as you indicate but this is neither the common or original intent. TSLA is only one frothy example but they still (a) make things, (b) have a historical record, (c) report on past, present and forecasted performance, (d) have widely accepted "value", (e) can be readily exchanged for something else of value, (f) have governance that is ultimately responsible for performance, even if they're not the major cause of said performance.

Everybody investing in the stock market is not a Reddit day trader.