No, but infections vary in severity. While most of us (not just children) couldn't have received a dose during 2020, receiving a dose later (including after recovering from infection) can improve ones immune response.
That seems well established: just as multiple doses of vaccine are better than one (with many arguing that the mRNA vaccines are really 3 dose vaccines rather than 2 dose), having an extra couple of doses after recovering from an infection gives measurably better immune response than just the infection alone. (Though I think that's lab measurements: antibodies, neutralising antibodies, variety of antibodies, etc., rather than evidence of actual benefit against disease.) Indeed, there were stories about "super immunity", though hybrid immunity seems to be the accepted term. (And that's also used for vaccinated people who go on to recover from infections, which seems to provide a similarly improved immune response.)
Yes, I know. That wasn't an uncontroversial opinion. I'm sceptical of it. There's a paper published suggesting they just got the calculations wrong, and I'm inclined to believe that one (though I haven't checked the maths). Many (though certainly not all) countries have gone a different way. JCVI also doesn't support chicken pox vaccination (and for a while didn't support HPV vaccination for most boys) so I think it's a bit less keen on vaccines than similar bodies in other countries. I suspect that's for cost reasons but I do wonder if there are other considerations.
Regardless, I accept that even if they decided it would be a good idea to vaccinate children, it's just too late now. They've said that repeated infections are about as healthy for children ("healthy children", that is) as vaccines and it would be very hard to shift that. Even if Novavax (or some other vaccine) became available for children and had no apparent myocarditis or similar risk.