I think you know that nothing is easier than diagnosing the world's ills, and nothing harder than inventing a realistic remedy.
Certainly, but I'm also trying to point out that anyone who thinks they fully understand the world, well enough to predict it ahead of time without imposing their predictions on reality themselves, is almost definitely wrong.
The optimist is wrong. The pessimist is wrong. The world will get worse and better, in ways we don't expect. The things we expect for the future are mostly extrapolations of the present anyway, and mostly won't happen.
And most of the world's problems are either self-imposed or get solved by the long, unacknowledged efforts of hundreds of thousands of people slowly chipping away at them...
"Hitherto, philosophers have sought to understand the world; the point, however, is to change it."