The reason why bitcoin keeps rising is because the demand increases. There are more people wanting to buy bitcoin instead of selling it. But when bitcoin hits a certain price, let us say $100k, will there still be people wanting to buy? The answer is yes. Some people are driven by what they see currently. They can't look at bitcoin at $70k and think that it would be smart to buy. But those who have been around crypto knows that when bitcoin is dipping that is exactly when you should buy and when bitcoin has reached a high value that is when you should sell.
But those who get FOMO and can't take risks tend to buy when the market is green effectively keeping the demand higher than it already is. If you already bought bitcoin when it dipped, should we be thanking those who get FOMO and allowing us to make profit? Haha. The early bird gets the worm. It is true and applies even on bitcoin.
every market has price insensitive buyers, like funds who buy every month regardless of price, or even retail who does DCA, bitcoin has Saylor buying often and usually at high prices...
so it's not always about FOMO
but you stand correct
FOMO is a force to drive prices higher