royalties aren't paid to developers from MTX/DLC btw, it's a one time deal most of the time. $60 for a full game is way more than plenty; within the 3 days of its release, cod:ww2 sold over $500 million copies. most AAA games sell well over the budget. the developer's salaries are pre-determined by a contract too.
i like DLC, but i don't like microtransactions. i haven't found a game yet that uses it "correctly"
Break down that 500 mil to all the wages paid out to every staff member and how long will that last a company? An employee may be under a contract, but with how volatile positions can be, it doesn't guarantee them anything.
This is just a superficial average. Companies can have hundred of employees working in a dev team. That doesn't even cover other teams that deal with the game, like publishers. A global director in publishing can be making close to $200k/y, not including any bonuses.
The additional revenue past the initial launch can keep companies stable and allow the continuing development of other content.
As much as it sucks to hear though, business means you need to turn a profit. You can't just break even. When companies fail to profit, they close and then you're forgeted out of games.