I think the "return to normality" is when the number of new cases reported each day drops to almost nothing and deaths are uncommon. Currently, in the U.S. we're about 70 thousand new cases a day, which is about where we were at the height of the second wave in mid-summer. Deaths are around 750 a day.
I think we'll get to normality eventually, but it may take longer than anyone has patience for, and that will only push it out further as people give up on social distancing and masking.
Time will tell if that's actually enough by itself to get the reproduction number less than 1. If everyone who wants a vaccination has one and yet we still have tens of thousands of new cases per day and hundreds of deaths and no downward trend, then I think continuing with masks and social distancing is going to be necessary.
I'm hoping that as the vaccination numbers go up, we'll eventually start seeing new cases drop off a cliff as the virus runs out of people to infect. (Though I suspect that we'll have problems for awhile with groups of people who hang out together and for whatever reason don't get vaccinated.)
I didn't pick +80% arbitrarily, that's where Israel has been for a bit (age +16 vaxed or recovered) and the stats are impressive. I expect the same in US unless a new more transmissible strain in the face of vaccinations emerges.
The problem for everyone else is that the vaccines aren't 100% effective. Also, we're not vaccinating children yet, and there may be some people who can't get the vaccine for medical reasons.
Another consideration is that if the virus is allowed to continue to spread, there's a real chance that it may mutate into a form that isn't stopped by the vaccine, and then we're right back where we started.
From a public health point of view, I don't see things getting back to ordinary people (and not just the foolhardy) having lunch with coworkers around the same table without masks on unless there isn't any significant amount of community spread going on.
I think we'll get to normality eventually, but it may take longer than anyone has patience for, and that will only push it out further as people give up on social distancing and masking.