Of course, this is not a question with an easy answer as your mileage may vary. But with the appropriate server-side configuration your WebSocket server can easily hold a **lot** of concurrent connections.
This is an example benchmark that was done on the smallest Digital Ocean droplet, that also had a couple of other Laravel projects running. On this specific server, the maximum number of **concurrent** connections ended up being ~15,000.

Here is another benchmark that was run on a 2GB Digital Ocean droplet with 2 CPUs. The maximum number of **concurrent** connections on this server setup is nearly 60,000.