It basically died when we became divided into two camps, neither of which can support any proposal if the other side supports it too. People are more concerned with feeling they've won an argument than actually achieving anything.
While the UK faces some ongoing challenges:
- Transmission bottlenecks in Scotland
- Dwindling opportunities for offshore wind construction
- Natural gas for heating in an old and poorly insulated housing stock
- Electricity prices tied to gas prices
- A generation of NIMBYs who don't want wind turbines ruining their view of transmission pylons and ecologically dead sheep pastures
- Lack of zonal pricing to incentivize more on-shore renewables
And needs to go further and faster I don't think energy generation falls into the same ideological divide there (though this may change with Reform UK and their questionable funding/astroturfing). Certainly net zero and 'green crap' remains contentious but from an actual building-the-thing perspective we're just quietly getting on with it.