chess.com could solve a lot of the site issues by using amazon web services and getting virtual servers. with aws you only pay for what you use. when the site is very busy virtual servers can be turned on and when there is less traffic they could turn the servers off and they would not pay for the time the servers are off. also it would help to use load balancers
If you visit the Jobs section in this site, you will find that they use state of the art techs currently available for Software Engineering, including AWS, GCP, Kubernetes, Docker, Kafka, etc.
This could just be a marketing ploy. How can we know for certain where these numbers come from? And how do we know they are active users? We need to dig deeper to get the truth than just feed off numbers mentioned in an article.
https://trends.google.com/trends/explore?q=chess
In any case, crashing your own servers as a "marketing ploy" is as bad an idea as your trolling attempts.
That link? That's just a year trend from Google on Chess and shows that in general that it was growing slowly in popularity, with a bump in the Summer, and a much bigger jump at the end of the year.