Yes, bees create new hives by themselves. Every year there are couple of swarming that include young queen leaving the hive to build new colony. In traditional beekeeping, the owner will catch the swarm, put it to new home and you've got another hive, which you either sell or use for more produce.

The problem is that a lot of hives die during winter (because of various form of illness and conditions) and the population couldn't sustain themselves.

Hives are only swarming if in very good health, and even then both new colonies are more vulnerable than the former one... It's certainly not "every year a couple of swarming" (how would that be sustainable anyway).

If they have to split hives forcefully, it's because they are not healthy enough to do it naturally...

Wrong information, sorry: during swarming the old queen leaving the hive and left the new queen her old hive.

Beekeeping is such an interesting hobby. Shame I hate (scared of hah) buzzing insects and stings!