Nationalised water in Scotland is no better than privatised in England and Wales, and has a higher rate of sewer leaks: https://theferret.scot/scotland-behind-england-sewage-leaks/
One thing of note about Scotland is that water is free (i.e. paid for by taxes) there.
But it’s unmetered, unlike most of the UK, and, as the other poster mentioned, cheaper.
https://www.fife.gov.uk/kb/docs/articles/housing/council-tax...
I think there is a good argument for metering water - it provides an incentive not to waste it, and potable water is expensive to supply and has a significant environmental impact.
It does need to be affordable even to people on the lowest incomes though.
So despite the best efforts of critics, they can't really show that Scottish water is any worse in terms of sewage outflows etc - if anything it is marginally better on that metric, and significantly cheaper to run. And the actual water quality is good, although that has a lot to do with incidental geography. Why would I want it privatised?