> If it's used by let's say 100users, It means one user has only 0.16core + 0.64GB memory. So an average laptop(4cores/4GB) or phone(4cores/1GB) is way faster.

This is overly simplistic. You're pretending that cores/memory are "allocated" to users, but really, a user might only make a few tens of requests, and the server only needs to spend a second or two servicing each request. On a server with only 100 users, it could very well be the case that a user has all 16 cores + 64gb available at the time they make a request. Also, as another commenter pointed out, you could use a large chunk of that memory for shared resources, and then each request might only need a few mb of memory to service a request.