Threading is something that I would recommend if starting a new project from scratch. When done well it will definitely improve performance. It’s only risky to introduce to a large project that already relies on being single threaded. That means it has very little awareness/safety of concurrent memory accesses etc.
Also worth noting that threads do not “isolate problems” or increase security at all. Because threads share memory with each other. Zero isolation or security. If you want those things then you need to put each component in a different process, like Chrome does with browser tabs.