The proposed duplicate explains that Stack Overflow has its own server due to sheer volume of traffic. However, it doesn't explain why Meta Stack Exchange has its own server, having only 5 active rooms compared to Stack Exchange's 60 active rooms.
To differentiate my question, I've changed my scope to specifically ask why Meta Stack Exchange has a separate chat server
The Stack Exchange network has three separate servers/subdomains for user chat.
- chat.stackoverflow.com (Stack Overflow)
- chat.meta.stackexchange.com (Meta Stack Exchange)
- chat.stackexchange.com (Super User, Server Fault, Arqade, Ubuntu, Mathematics, Web Applications, and all other SE sites)
Why do Stack Overflow, Meta Stack Exchange, and Stack Exchange use separate, independent chat servers instead of sharing one subdomain?
Having separate servers means that users can have three separate chat accounts without even realizing. I only recently realized that, in addition to my network and per-site profiles, I also had separate accounts for Stack Overflow Chat, Meta Chat, and Stack Exchange Chat.
I read a comment speculating the servers may have been separated to improve performance. That reasoning could explain why Stack Overflow (34 rooms) is separate from Stack Exchange (60 rooms). But if performance were the reason, why separate Meta Stack Exchange? As of posting, Meta only has 5 active rooms
*Note: This question is not about unique per-site domain URLs. See Why do some Stack Exchange sites have their own domain names?