The simple fact is that you are not paid for the value you create. You are paid based on the salary you can demand. For performance engineers, $10 million/year/person opportunities are kind of rare, meaning that you can't demand close to that. Your alternatives to big tech are things like wall street, which pay very well, so you can demand a higher salary (and/or higher level) than a normal engineer of your skill would get. However, this is nowhere near the value of the work.