Capitalism is neither good or bad. It's a tool. It's the people that design the system that hold ultimate responsibility.
All the things you say about things having been tried previously applies just as much to socialism, Marxism and other forms of non capitalism economies.
Slow incremental improvements pay off dividends in just the same way that slow incremental worsening has made things worse.
I think faster broader changes would help more, but that doesn't make them easier to implement.
Yes, there is a despair with how the world is worsening. We have a lot of things to blame for it. Facebook, trump tax laws, tax havens etc. Yet people continue to use facebook and continue to vote for Trump.
What needs to be done is fight and push for better candidates and better policies. Many are doing that but not at the level that is required. When was the last time you went to a political meeting? Or a rally or march? Those questions are rhetorical. I know I haven't been in a long time. We have become complacent and despondent as a society. Things are harder, but also easier. We have lots of conveniences now that were unthinkable at the times you mentioned where things were subjectively better in the past.
Things were not better for women and minorities. Things were not better for child workers. Things were not better for lgbtqi people. Slaves were not better off by having a UBI. Please be aware that ubi means you have no obligation to work. Any income from work would be on top of the UBI. With advancement in productivity. I don't see how society will function without UBI or cutting hours significantly. Jobs in transport, logistics etc will all go. AI will kill many more in communication.