And what's the level you're willing to call normal?
Several posters have replied with numbers between 100,000 and 30,000 yearly deaths, roughly 270 to 100 daily deaths. Still a far drop from where we are today even for the larger value.
That's that answer to the question. We're back to normal when we're down to level we collectively decide is low enough. Pick number or we'll all just assume 250,000, 700 daily IS your normal. We're there. It's normal today.
The problem with defining the acceptable number is that, just like the need for mitigations going forward, is that it's likely to be regional. It's really problematic for a nation our size, and with such diverse population densities.
For example, we have lost roughly 1500 Montanans in the year since our first death. 4 people a day. Most people out here, myself included, will take that number. Our horrific October-January aside, we now ride at roughly 50 hospitalizations at any given time. Our hospitals can handle that, even if it means a person in the literal middle of nowhere needs to be transferred to Missoula, Billings, or Bozeman. I'll be honest, with roughly 40% of eligible people in my county started on vaccination as of the latest weekly update, if someone in Pray (population 750) doesn't want to participate in vaccination that's quickly becoming their problem.
The problem with the above is that, adjusted nationally, that death number becomes 495,000 people. 1,320 per day. That's too many for myself and, I hope, most Americans, to want a full return to normal. Thankfully we're currently approaching half that, but it's still too high. It's why there is still support for mitigations in the face of vaccination until numbers go down.
If you take the hospitalization number adjusted for population, it amounts to about 16,500 active admissions. So long as they're spread out nationwide, we could probably handle that. We're roughly double that number now according to the CDC tracker. The issue with our current state of affairs is a matter of disbursement. Images like we had coming from LA County this summer, or the NYC metro area last Spring, scare the everliving daylights out of people and bring mitigation compliance way up. It's probably why population centers have higher vaccine acceptance.
I think somewhere in the neighborhood of 5 cases/100k/day (~17,000 cases/day). So long as deaths are distributed nationally and not in hot clusters, that probably means somewhere around 150 dead/day, or 55,000/year.