Market cap arguments lost me a lot of money. I wonder if there's just some flaw with this line of reasoning or I'm just unlucky and the market is too bubbly/irr

Market cap arguments lost me a lot of money. I wonder if there's just some flaw with this line of reasoning or I'm just unlucky and the market is too bubbly/irrational right now. For example another weird stock is Snowflake, which is currently at 100B but they themselves claim their total addressable market size is only 70B. Ditto for airbnb and doordash.