even selfish and thus fitter individuals which are helped by altruistic ones usually carry some altruistic genes which they propagate.

It’s more useful to model the genes as selfish, not the individuals. A queen bee/ant won’t survive long enough to produce fertile offspring if her infertile offspring, each a genetic dead end, doesn’t provide for the hive/colony. That genetic programming isn’t altruistic because it doesn’t help rival colonies/hives, only their own.

So no, the individuals aren’t free riding on others’ altruism. It’s more that genetic coding for social groups is advantageous to the gene, even if localized applications of those rules might seem disadvantageous to the individual in certain instances.