I'm pretty sure infinite timeout also breaks the application, in a way people rarely realize that it is because of the timeout. People would rather think it "just didn't work, don't know why" instead of being very clever and realized "it must be low timeouts!!!"
When it comes down to UI there are even more options. Since you have a human on the other side, you can transfer to them the responsability of deciding when to timeout. The UI certainly shouldn't become completely unresponsive while a request is being made.
To be pedantic though, infinite timeouts don't break applications except some rare cases of resources exhaustion. If an application is completely unresponsive, it is dead for good, not because of the timeout, need to fix the root cause (often resource exhaustion like swapping or it's waiting on another IO or service that's frozen).
You don't need a timeout, you need a "cancel" button.
This happens regularly when I open large files in some app, they take a fair bit of time to load, Windows offers a popup to kill the app after few seconds. Have to carefully wait and not click anything.
Let's say 10 seconds, typical intuitive but bad timeout. This will cause requests to fail for no reason other than users are in Asia or Africa, high latency. This will break the application when it's used or deployed across datacenters because high latency. This will cause requests to fail when the server is a bit busy (couple seconds more to process requests). Worse, it will cause chain reactions under load, creating more retries and even more load, causing other services/servers to timeout too.
Better go for a long timeout. A long timeout doesn't break the application.