Hatching eggs takes quite a lot of time. More time than the player can really afford to worry about. In the beginning of the game, when they're first getting eggs (such as the sinistea egg), there's no real chance of hatching it in enough time for it to be useful in the early-game foraging grind.

If the egg was closer to hatching, there would be more of an incentive to run back and forward between foraging, because hatching it would allow it to become immediately useful.

I should consider adding some method of earning egg steps. It doesn't appear I can spawn Pokemon with egg steps, but perhaps I can add them later. I do not want to decrease the time it takes ALL eggs to hatch.