I've always thought that ecological conservation work might be a decent solution (to redundant mine workers and the like refusing welfare/UBI). Reclaiming former mining land for forests via tree planting and land stabilisation etc is an important job that will pay dividend in the future. Not really hard to re-skill for that, it's still hard manual labour, and it's a positive for the environment. There's also forest fire mitigation/fighting work, volunteering and so on.