“healthcare, education, homelessness and poverty, food waste, climate change”

Is it just coincidence those are all areas with heavy government restriction? People have produced innovative solutions: low-cost catastrophic-only insurance plans, “micro-houses” in LA for the homeless, home-schooling co-ops — and those insurance plans get banned, the micro-homes get demolished for non-compliance with city rules (strangely, no rule against making people homeless again!) — from the outside, it quickly becomes apparent that there are powerful factions with a vested interest in preserving rather than solving problems.

Work really hard on one part of one of those problems, without threatening to upset the powerful incumbent forces, you might make a small difference — or pick a less obstructed field and achieve much more. Pick your battles carefully!