Carpets are the bane of my life. A property should be let without flooring, meaning the incoming tenant is responsible for laying flooring and also removing it at the end of tenancy. The are lots of reasons why this is the norm in social/affordable housing.
Firstly, cost. If the landlord (us) were to lay flooring, we would be responsible for replacing it when wear and tear occurs. This is not necessarily an issue (other than cost), but people are more likely to look after the carpet if they pay for it themselves. Next, there is the issue of taste. My experience is that the majority of people want to choose their own flooring - not just colour, but also quality. If we were to lay a cheaper carpet to make it affordable across hundreds of home, the likelihood is that the majority of our residents would want to replace it themselves. If they were to remove our carpet and replace it with their own, who then is responsible for replacing it if it became damaged? Us or them? If they left our carpet down and laid a carpet on top, then there is unlikely to be enough clearance under the doors and they would need to plane them back. Again - the cost of this, who is responsible? If they/us removed their carpets later down the line, the doors would have a big gap underneath and the room would be quite draughty.
We also don't take deposits from incoming tenants, therefore if carpets were damaged/needed replacing at the end of tenancy, we would have no financial recourse to reclaim any cost of this from the tenant.
We could clean carpets at the end of tenancy, but then there is the cost. We are a small housing association (less than 1000 units) and our budget for fixing any issues at the end of tenancies is approximately £11,000 for the entire year. That includes any cleaning, damage to walls, carpets, replacing appliances etc. We do ask tenants to return the property to the standard at the start of tenancy (which is usually really high) but if they don't, we're left with the cost to remedy this and also running at a void loss (when a property is empty and we can't let it out as it needs repairs).
So yeah, the simplest way is for tenants to lay their own flooring when they move in, and to remove it on the way out. What happens in practice though is that when a tenant moves in and lays their own flooring, when they eventually end tenancy (either through choice of death), they or their next of kin don't want the hassle of removing the carpet. In this instance, we can facilitate an agreement with the new incoming tenant to accept the carpets as a gift, but then they are responsible for removing/replacing them throughout their tenancy. If the incoming tenant doesn't want to accept them, we would ask the outgoing tenant to remove it, or we would do it at a cost.
And that's just a tiny insight into carpets.