That's the construction time alone, including planning it took over ten years.
It also has the advantage of using sections of existing railways and railway corridors.
All that said, it's still remarkably quick by the standards of major infrastructure projects.
There are definitely situations where trams/light rail are more efficient than buses - basically if you have lots of people to get from point A to point B in a relatively short period of time.
If you've got the money and space to segregate them from traffic then it's great, it's basically like...
I mean, I'm not claiming to be an expert on every town's public transport [hastily checks thread to check he hasn't claimed to be an expert on every town's public transport].
Unless you're simultaneously complaining about there being too much traffic in Burgess Hill while disregarding a bus that...
Brighton may well be different to Burnley, but that's not what I'm basing my opinion on.
I'll grant you that getting public transport from somewhere outside Lewes to East Grinstead was a pain, because it took two changes and two modes of transport.
And going from suburban Leicester to Anstey was...
There are a huge number of journeys into and around town/city centres for which using the bus/tram/train is not only obviously preferable, but is obviously preferable by a vast margin.