No, there will always be some people more affected and some less affected but because of the huge size of the population this will still amount to a very large number of people being significantly affected ( eg long COVID, getting it several times a year, being hospitalised etc). This means that we still need to respect the effect of the virus and take some actions to minimise spread. We can't just say - well I'm not affected nor anyone I care about ( so far) so we don't have to do anything. Well we could say that I suppose but only if we don't care about the population as a whole.
At the moment Covid is more dangerous than flu because it has not been in human hosts for very long and we've not go as much immunity etc. In time I think it will be more like flu and we will be able to tweak vaccines every year to reduce effects/ spread. However, because of the vaccines we already have and people having had it and having better immunity than originally, it is not as dangerous now as it once was, but it is still something significant we need to pay attention to.
So, if 10% of the population gets long Covid that means on average 3 children in each class will get it at some point. So it makes sense to take precautions to reduce spread. Eg children not going in to school with COVID, good ventilation, no overcrowding etc.
I'd also say that if people have COVID they should stay at home as much as possible for the first 5 days. Schools and employers should accommodate this as on average it will mean less spread, fewer people affected, less chance of people being off for longer periods with complications.
Is also say that if you have COVID and need to go out, then wearing a good spec mask would be a socially responsible thing to do.
I would support air purifiers in each classroom to be honest. It would be a few hundred pounds per classroom but would really reduce the level of spread. It would also improve attendance because it would help reduce spread of other viruses.
It isn't just " do lockdown or do nothing" there are intermediate easier things we should be doing in my opinion.