Fast construction speed was an advantage even 30 years ago, and so is the lower number of full time employees needed to operate a CCGT plant vs. equivalent capacity from a nuclear or coal plant. But note that the turbine revolution arrived back when the US was still building coal and nuclear plants. They weren't built just for "green washing" reasons or for avoiding legal battles.
[1] https://www.eia.gov/dnav/ng/hist/res_epg0_r5302_nus_bcfa.htm
And if it's an illegal leak, maybe it needs some help to flare.
Its arguable what the correct timescale to consider it is. Personally I think 100 years is too long given methane's potential feedback effects. IE, warming causes methane to be released from Arctic tundra melt causing more warming, etc.
And there's also the issue that the higher the concentration of methane in the atmosphere the longer it takes to decay.
Now that it is closed, and there is no smoke - they can see not just the towers, they now see a long way behind them as well.
Best guess: you're confused by the word "smokestack". Smokestack is a synonym for chimney. The power station is closed. The chimneys are still there, but there's no smoke coming out of them.
It's very clean when compared to coal, 50-60% less CO2.
Gas emits a relatively low amount of CO2, but a much higher amount of methane, which is a potent greenhouse gas (easily 10x of CO2, 50x as much depending on how exactly you measure it (e.g. methane has a shorter atmospheric lifetime than CO2)). Measuring only CO2 here is pointless.
Err... no.
Natural gas is methane, to a good first approximation, but if your plant is emitting methane, it means your plant is not operating efficiently. Natural gas power plants burn methane, producing CO2 and water.
Edit: if you're talking about production leaks, coal mines emit methane, too, and there's not even a token amount of effort to stop it, nor any incentive to do so. With gas production, every cubic meter that leaks is a cubic meter you don't get to sell.
2. A gas turbine can be up and running in days
3. Green washing - it's "clean" energy for some definition of clean, certainly compared to coal
I'm exaggerating a bit on points 1 and 2, but the fuel costs are cheap and you can setup a gas turbine plant comparatively quickly compared to a coal or a nuclear power plant. Most people don't care about a gas turbine plant in their backyard, but a coal or nuclear power plant? You're facing a multi-year legal battle that's going to cost you millions of dollars. You have to do environmental impact studies that are going to cost you tens of millions of dollars. There's a lot of complications for how to handle the waste (not just nuclear: coal has SOX, NOX, fly ash and pot ash wastes that you must manage) that cost tens of millions of dollars. A gas turbine is quick, cheap, and easy. Guess which form of electrical power generation is proliferating?