To use Laravel for such problems, the idea of working, but not very common. As for performance - it all depends on how much money you are willing to spend on infrastructure. And so will cope fine if clients are well up to 1000 online. Then you will start the problem of vertical scaling. You can still stall it, but still it will end at some point.
If you want to keep a lot of connections https://nchan.io/
will suit you perfectly.