5G broadband can handle work from home activities just fine if you have a strong signal. However, if your 5G connection drops or experiences congestions due to many people connected to the same tower, it will be your worst nightmare for video calls and upload/download. You can buy a prepaid sim, subscribe internet and test it according to your use case. Also, 5G definitely cannot beat fibre in terms of latency if you play games.

Your best bet is to continue using Time fibre and invest in good mesh system for your home.