The problem is only half the population really followed through. These measures are still needed more because half the population effectively thinks COVID is no big deal or a hoax.
Given US values (e.g. "don't tread on me"), 15% of the population would ignore restrictions. You'd also see the same thing globally, sometimes because of values, sometimes out of economic necessity.
We never had a chance to vaccinate the world quickly enough, either. Up until delta, the mRNA vaccines might have been able to eradicate it, but delta was circulating in India around when those vaccines were approved. The logistics and manufacturing capacity to deliver them to rich countries was still 6 months away.
People ripping down mask signs, spitting on people, arguing at the doors to a store, etc.
There's a lot of people in the US arguing that mask mandates and other medical precautions are "violating their freedom".
So I drove over to their place and they leant me some stuff, we were all paranoid so they left the stuff in the garage, I drove up, waved to them on the porch and loaded up my car and headed home. I did need to stop and get gas before getting back on the freeway, at the gas station there was a little mini-mart. There were four people inside, none of them had a mask on. The gas station is next to a Denny's or similar, their dining room was closed but there were people waiting INSIDE and UNMASKED for takeout.
That's why we can't have nice things, even if your town/city collectively was pretty serious about lockdown, the next town over might not be and their citizens are coming into your community to work or whatever else. The only enforcement is the local sherif and if they are a crazy gimme liberty or gimme death type they aren't going to enforce shit.