None, more than likely they'll go back to peoples houses and drink more, so it's good for off sales too ;-)
If it's bad enough that people can't mix households, then sorry but pubs should be closed, as you can't help but mix households there. I'd even suggest restaurants should be only takeaway too, but we have to have an economy of some sort, and as you can still sit in an office, supposedly covid safe, but who's checked ?
Nobody has checked mine, and it's certainly not covid safe, it's exactly as it was in March, apart from ony 1 person is allowed in the small kitchen area at once, luckily I've only been in it 4 times so far, and it's nearly a month before I have to do so again.