Person A, investor puts in $100k
Person B, employee gets paid $100k
Company fails.
Person A lost $100k
Person B gained $100k
This is why person A gets the lion's share of the rewards if the company succeed. Person B risked nothing. Person A risked $100k.
The typical retort from Person B is they could have gone to a different company so their risk was to work for this particular company. For example they could have gone to a FAANG company and made a high salary but instead went to some startup at a lower salary on the risk that it would succeed. From one POV that is a risk but it's not your money until it's in your hands. Future money is similar to saying well "if I won the lottery tomorrow". Until you do actually win that money it doesn't really count. You can use that line of reasoning in negotiations (you want me to join your startup but I have an offer from a FANNG company, sweeten the deal if you want me). But after that you didn't actually take a risk relevant to the company. Instead you made a choice to be paid X amount for your labor.
Note: I've never been on the investing side, only the employee side, but for some reason I've never felt ripped off since I knew I was taking no risk.