Your constant, tiresome refrain here is that society isn't actually better, or we are looking at the wrong stats, or something. Happiness does seem to be dipping, and it makes little sense. But the other stuff is not true. The suicide rate is not climbing, for instance (see below). The US is an outlier here, which is also puzzling. AGAIN: no one says that everything is PERFECT, only BETTER in most categories.
Finally: "Declining life expectancies" is pretty misleading. In the USA this is true, for the last couple of years, and 100% attributable to the opioid epidemic - and overall it is WAY up from any earlier time. ANd again, loneliness is unmeasurable. We have no idea whether it is rising or not.
Link: https://ourworldindata.org/grapher/suicide-death-rate-by-age