After a real life conversation I'm confused and worried

Freehold and leasehold

Freehold I understand to mean the land the house is on, is owned by the same person the house belongs to

Leasehold I understand to mean the land the house is on belongs to someone else

What if on the leasehold one, the person who owns the land decides they don't want a house on their land any more? Can they knock the house down?

My own house is freehold so I don't have that problem, but I'm worried in case Mum ends up in a leasehold house and the landowner decides "we don't want a house there any more" and books one of those vehicles with the big concrete ball that then smashes down the house, leaving the person who was living in the house, with no home