I once worked for a company that was building among other things a videoconference app. The quality of the product only really started to increase when employees were sent home during covid and they started using their own tool.

There's always some tiny little thing which is missing for someone. If you demand 100% completion before you can switch, you will never switch.

> we need to fund their improvement, and use them once they are ready

That would mean funding for a long time, without getting any tangible results (since you refuse to use it until it's "ready") until the very end. The end result would be that the funding is abandoned after a while, and you never switch.