The Hypixel servers are at maximum capacity during the peak 4+ hours every day, meaning additional players cannot join. This is an obvious issue for other applications.
This isn't a limit of our ability to procure hardware, but instead a limit of one of our 7-year-old monolithic applications. We're working on increasing its stability at high player counts, but it's a totally separate issue from server provisioning and cloud vs bare metal.
I see. Out of curiosity, what is the limiting application?
An in-house application that we (I) developed in order to handle game balancing, queuing, and overall network state for a multi-LB Minecraft network. The application's name is MasterControl, and it's architecture and design (or lack thereof, it was literally the first program I ever wrote) has been the source of many headaches over the last few years. Had I known years back that we would see the kind of player numbers that we have this year, we 100% would have completely rewritten it into our modern microservice architecture.