Leasehold or Freehold?

It's not enough that you have to look at which area a property is in, how old it is, how many bedrooms it has, is there a garden, is there off-road parking, are developers planning to bulldoze the block and build a swimming pool?

Oh no, just to add to the confusion, you have to see whether it's offered as freehold or leasehold.

What's the deal with the latter?

I can understand it with flats, where several people occupy dwellings on the same piece of land. But all houses should be freehold. If I buy a house on a piece of land, I should own the land to the core of the Earth, and not pay some faceless third party.

And why go charging me extra for freehold? Or varying the length of freehold from 99 to 999 years? It's my land until I decide to sell the house that's built on it, and when I sell, even if I'm 1,001 years old, I'll sell the land too. Simple.

But of course the words 'simple' and 'buying a house' are strangers to each other.