It’s been and seriose issue for decades.

In poor urban areas few have gardens. So to allow poor to continue to grow some of their own quality food. Post WW2 the allotment scheme was kept for such areas. As for many it was the only option.

For anyone older we hears about right wing effects to sell off the land at least every 10 years or so. Waiting lints have increased to decades in many areas.

The land is designed to be cheap to rent. But requires use as an allotment. So age is often how they change hands.