I wouldn't trust our government to get it right to be honest. It would require a lot more investment than people probably realise and going by the hostility anytime anything is mentioned regarding reducing car use, it would probably be a way of losing votes in Scotland even though it shouldn't be.Try putting Luxembourg free public transport into Google and read all about it.
Has been in use for the last 3 years. Funded by the state taxes.
I don't think First are perfect by any means but I feel like they aren't anywhere near as bad as some of the public would have you believe and I've used them regularly since I was a kid.