Opening bidding for another PSB is unrealistic. The problem is its expensive and there is no money.

The Scottish government could raise income tax and take over BBC Scotland if it wanted I guess?

The real problem is the license fee hasn't risen with inflation for many years for political reasons. I personally think the license fee should be abolished, alongside council tax, and a new property tax brought in that covers both local government and public service broadcasting. That would be a fairer system and gaurentee long term funding for the BBC and other PSB services.