I’ve also heard salaries over $£€70,000 no longer increase happiness.

No, that study was debunked. Turns out that some subset of unhappy people will remain unhappy even if you give them all the money in the world, so looking purely at the least happy people in America, you’ll notice that their happiness stops going up at $75,000 in 2010 dollars. But if you focus on people who are already on the happier side of the spectrum, more money keeps buying them more happiness, even if the slope of that relationship tapers a bit.

Side note, the way the two sides reconciled their methodologies, that produced different results, was a really interesting way to perform science, and should be followed in the future whenever there are well respected studies that contradict each other.