They simply didn't care. There's a whole genre of people using thermal imaging cameras to see vast quantities of methane being released by oil wells and other fossil fuel infrastructure from things like unlit flares.

The Inflation Reduction Act imposed a tax on methane emissions by the oil and gas industry at high-emissions locations, so now suddenly people are interested in both collecting the tax and in preventing the emissions to avoid the tax.

It turns out if you don't regulate something, and it costs significant money to fix, even if it is known to be harmful to people, the environment, and is potentially explosive, companies will choose to keep money vs spending money to fix the problem.

Trump slashed environmental protection laws during his administration and pretty much castrated the EPA. Things were getting better before that thanks to a lot of things enacted under Obama. See this list on what he removed, particularly the demand for oil and gas companies to report methane emissions, but also a ton of other emissions and pollutant laws.

Just one more reason he can't be allowed back into office...

Good fash, bad fash, afab.