Not a foster carer but interested so please be gentle if I am not going in the right direction with this.
With local authorities being strapped for cash, why can we not use large central empty properties in each town to house children in foster care from around secondary school age onwards. I am not talking about the horrific care homes of old with their stigmas, harsh regimes and abuse hidden away in remote places. I hope we have moved on from that towards kindness, support and life skills building in a nurturing environment where children are listened to and part of the planning of the service to them. There may be children still at risk of harm not able to come into a foster home due to shortages of carers and this could be a workable alternative. It would keep children close to their communities.
If the right skilled adults - social worker, support worker, care worker - were put in place (24 hour round the clock), a larger property may be a great place to build those independence skills and life long peer support networks. (Similar to Halls of Residence in Uni's but with more support/staff as the children would be younger). We have a massive shortage of foster carers and many due to leave in the next few years due to retirement.
Just a thought.