The pandemic exacerbated what was already there, surely. I would give you more credit that to claim that our current devisiveness began with the pandemic.
In the beginning I hoped the pandemic would bring the world together, like an invading alien we all had to band together to defeat. But sadly it was not to be. Non-pharmaceutical interventions were presented as self-protection when they are not. Masking, distancing, and lockdowns are logical steps in the fight against a highly infectious pathogen against which we were otherwise defenseless. However, from an individual standpoint, you stood a reasonable chance of survival even if you were infected, so ignoring such restrictions entailed only moderate risk.
From a population standpoint, that is, the standpoint of an epidemiologist, the picture is much different. Many thousands will surely die: we just don't know who they are yet.
Masking, in particular the use of cloth masks or surgical masks, does little to protect the wearer. But a surgical mask protects a vulnerable other: that is why surgeons wear them. Cloth masks do likewise. Aerosol spread is trickier to control, but the fact that COVID-19 spreads that way emerged as the pandemic unfolded. Everyone seems to forget that this was a moving target, that scientists were scrambling to understand it and yet were called upon to make recommendations. The dissemination of information was complicated by the Chinese government, yet individual Chinese scientists hastened to make information public, at great personal risk.
Would people have been more amenable to appeals for acting for the good of others? Given the ascendency of individualism I have my doubts. When vaccines were released my doubts were born out and it is even worse now. Measles is beginning to re-emerge as vaccine coverage falls below the level needed to protect everyone regardless of vaccination status. It will spread, and it will be mostly children who will suffer and die. Yes, measles can kill. It inevitably kills a small percentage of those infected. How many thousands of children will have to die before we, as a society, a population, wise up?
How many excess COVID-19 deaths occurred because non-pharmaceutical interventions were poorly implemented? We will never know. In the US, counties in which vaccine resistence is high continue to out-pace others when it comes to deaths from COVID-19, so, as with measles, we can get some idea of the human cost of misinformation.