> so in theory everyone's lives could end up better off over time

they did. The innovation that happened in the past 100 years meant that almost everyone (in the west at least, and in a lot of developing nations too) has the access to transport, clean water, electricity, information/communications etc.

And because everyone has it, people such as yourself see it as a baseline, and forget that it is benefits being received that they didnt invest in personally. This is what the tide that lift all boats are - and because everybody is lifted, those who complain about lack of the trickle down sees the high-flyers benefiting enormously while their own benefits aren't "visible".