I wanted to get to a desktop and illustrate a few points in just my state of MT. Since nobody lives here, but those that do live in just a few pockets. I still laugh when people refer to "the big city," when it's barely a Cincinnati suburb where I grew up. I have recently visited or live in each of these areas for youth fencing and swim tournaments, so can speak to local attitudes. Hospitalizations per county are pointless, as we do so much transferring and intake of underserved, ultra-rural areas.
Gallatin County (Bozeman, MT State Univ., gateway to Yellowstone travel): 34.4 people/mi^2. 48% total fully vaccinated, 55% 12+, 57% 18+. About the best you can ask a rural state in terms of non-vaccine mitigation. 24 cases/100k, 8.4% positivity.
Yellowstone County (Billings, big shopping hub for Wyoming and ND folks to avoid sales tax): 49.1 people/mi^2. 41%, 49%, 52%. People masking roughly matches those vaccine numbers and businesses couldn't care less. 38.5/100k, 10% positivity.
Missoula County (Univ of MT, easiest airport to Glacier, serves a large # of native counties for healthcare needs): 42.1/mi^2. 55%, 63%, 64%. 40.4/100k, 17% positivity. People let their guard down, mitigation used to be awesome here. The youngest ages groups have the highest spread, so it appears schools (K-college) are driving the recent outbreak there.
Looking at these rates across the three "big cities," it's not an either/or. It really is both. If it were just vaccines, Missoula would be wiping the other two across the floor. Bozeman has hit a better middle ground, for now. Either via businesses or government, mitigations need to be enforced until enough people are vaccinated. At a minimum, until parents can choose whether or not to vaccinate their children. Because <5 may take a long while yet, let's meet in the middle and say 5-11 needs EUA for a few months' time before we really let our collective apathy run wild. At least with everyone over 5 eligible that would get us to 93% of all Americans that could have a shot, and nearly 100% of those at risk for the worst of COVID.