It is very easy (relatively) to build a SaaS platform that serves this amount of traffic and this can be done by even a one determined individual or a small startup team.
I don't think it is useful to measure the size of the company in the amount of requests they are serving. Revenue/number of employees are much better measurements saying more about the type of things that are/can be happening. They may have relatively low margins per request and need to get to 4B to get by to pay for couple salaries?
Seems like I spent quarter of century in this business for naught.