a question about leaves from trees

The falling leaves will block drains and as others have said make paths slipery.
The leaves that fall on your lawns will make them rot and kill the plants underneath. They need the light.
The councils can compost the leaves with garden waste and provide good compost.
We have a lot of what are "next doors" leaves.

Yes, they need to be cleared as others have said. Digging them in wouldn't work, would disturb the tree and trees do not like being disturbed; a change in soil levels around the tree or disturbance of the roots could cause it to die.

Leaving them in woodland to rot is normal.

Leaving them on pavements to get slippery can be dangerous.

Leaves do seem to take longer to rot than another garden waste so we tend to keep them separate (and damp).

The answer is that in some places, for good reasons leaves need to be cleared and other posters have listed these, while in in other places they can be let lie.

What matters is not whether they are gathered or not but what happens once they are gathered up. Most gardeners, if the leaves are not too many compost, them and return them to the soil, where they want them.

Most if not all local councils run or contract in green composting schemes, where they deliver all the leavesand green material they collect, plus the contents of green bins at tips and take them to these industrial composting schemes and then either sell the composted material back to gardeners or use it to improve the soil in council parks and gardens.

Our local village pavements and road edges still have wet slippery leaves on them. I suppose the council had had to cut back!

I sweep them up and put them on my compost heap.

Infoman surely you’ve heard of leaves on the line? As others have said, on pavements and roads, wet, slippery leaves are a hazard. Presumably councils don’t want to be sued by litigation-conscious people who have slipped on them, for their negligence in failing to sweep them up.
I don’t know what councils do with swept up leaves, but Northumberland has a successful garden waste collection and recycling system. People’s garden waste is composted and sold back to them. Perhaps that’s where Northumberland’s leaves go.

I have several trees in my garden. The leaves from them fill my several compost bins plus numerous black bags every year. If I were to put all those leaves round the trees themselves, they would make large mounds round each tree. Digging them into the soil wouldn’t be practical.

In cities the leaves block drains and become very slippery underfoot. If left on soil insects, worms, and bacteria will allow natural recycling so that the goodness is returned to the soil. I vacuum and shred leaves from around my home and kept damp and left alone for a few years it provides a lovely leafmould which I work into the soil.

In tree-lined streets – which are always attractive – the leaves fall mainly on the pavements. As they rot and when it rains, they become slippery, so need to be removed to prevent accidents. They could be buried at the bases of the trees but that would take rather more time and effort than simply sweeping or sucking them up and would have to happen over some weeks as leaves don't fall in one go. That is really not an economic use of limited council revenue. However, if the swept-up or sucked-up leaves are taken to a green waste plant, as they are where I live, they are then allowed to rot and become humus.

Are you saying the LC won't allow you to bury leaves? Really?

I imagine it would be quite hard to dig in leaves around the roots of a tree and may even compromise the tree itself.

You can be buried in private land in UK with certain restrictions and you certainly can in NZ as I recently attended one in woodland owned by the son of my decerased friend.

Ive often wondered that.