They are asking not for an AI to solve these problems, but to take the brains of those people who develop AIs and put them to use for other, more productive fields. Which is something I tend to agree with and would add advertising, finance/quant funds and cryptocurrencies into the mix - humanity doesn't need either of these for survival.
However, the core problem is that we have solutions for all these problems with technology that exists today:
- energy can be produced by solar, wind and for baseload geothermal and biogas. We might need to shift certain high-consumption industries such as smelters to seasonal and time-flexible production though, to accomodate a lack of solar power in winter and at night.
- pollution is a solved problem as well. Place filters on the exhaust stacks of industries that absolutely need some kind of burning stuff, transition ICE vehicles to electric vehicles and eventually, switch a lot of the traffic load of individual cars to a mesh of public transit (tramways and light rail), to remove the emissions caused by tires.
- affordable housing is a solved problem as well. Build socialized, community-owned housing like Vienna does, nationalize large landlords, improve infrastructure in rural areas to remove pressure on urban housing, and regulate where large employers can set up shop to avoid concentrations that cannot reasonably be supplied with workers and traffic.
- content moderation is a plain and simple matter of employing enough people
- "loneliness epidemic"... that's the only tough one. We do know what causes loneliness, and a part of that is that young people have to move across the country, often enough across continents, to find gainful employment. Fixing rural infrastructure should help a bit, as should better availability of decent affordable housing - IIRC, a contributing factor both in Japan and Italy was that young people can't afford to move out of their parents' homes or if, then only into essentially sheds, so neither is conductive to invite a potential partner to.
The problem is, politicians today are not driven by what science and history has shown to be successful, they are driven by party ideology and populist bullshit. That leads them to take decisions that make situations objectively worse.