Variants are already becoming an issue in NY. It is happening.
That’s not to say we won’t defeat Covid by summer/fall. Just saying it’s yet another wrench in the works.
I think there is also an issue with the definition of “normal.” We may never ever return to the old normal. Temp checks, vaccine passports, masks on public transit.. lots of “new normal” possibilities.
And of course the biggest certainty is the rate of vaccination once we have enough supply — do enough people willingly get vaccinated.
I do wish we were planning on extensive use of vaccination passports. As Israel is doing, it gives you the certainty you’re seeking: As of September 15th (for example). you can go to a concert, full capacity restaurant, museum, theme park — but only if you’re vaccinated.