Depends on the motivation to use - self-hosted option is of course bad for privacy, but still good for security - you could use a browser running on a separate machine, effectively making it a physically isolated sandbox
that's a valid point as well. This pretty much results in a privacy vs security choice, you either run it in infrastructure you fully control at the loss of privacy or some anonymous service, where you could have privacy but loosing the security.
Although one could argue that using an anonymous hosting service, there's still a risk that whoever is running that infrastructure could monitor your activity meaning that effectively you have neither privacy nor security.
there are plenty of anonymous hosting services out there in which case it would be exactly the opposite: "good for privacy, bad for security"