If you tie that 7% with a mask it’d be interesting to see how much it is lower. Of course mask wearing is a pretty weak intervention considering that there is a wide variety of masks and differing compliance. For that reason, I doubt you can rely on it heavily.
My guess is typical mask wearing might be fairly effective for short exposures, but less so for longer exposures, like longer journeys on public transport or being in a shared office for hours. Things like ventilation would also be a factor.
As far as the UK goes, we're not relying on masks at all anyway. Mask mandate on public transport, shops, etc., ends next week, the mask wearing we briefly reintroduced (and I mean briefly, it's only been in place for a couple of weeks) for secondary schools is being lifted from tomorrow.
We're also planning to end compulsory self-isolation entirely from 24th March, and that might be brought forward.
Basically betting that vaccination is sufficient to keep cases and severe impact at a tolerable level. Tolerable for who is another question.