The standard of living has been in decline for a long time

Citation?

Median real weekly earnings have risen over the last 40-ish years, meaning the average person makes more today after taking inflation into account, than they would have 40 years ago (or almost any point in between) for the same job at the same point in their lives. It's also pretty consistent across racial demographics. We're down from a peak in early 2020, but that peak was during an unprecedented change in labor where a lot of people left the workforce to receive increased unemployment instead. If you cut out Q1 2020 - Q4 2021 (the main part of the lockdowns), you get a pretty steady increase in real wages.

Poverty rate is steady or declining, and real GDP per capita is also increasing. By all metrics I can see, things are getting better for the average worker pretty consistently, and have for at least the last 40 years.

News sites focus on the negatives and average people complain about what they don't have, but that doesn't change the stats. The average person seems to be better off today than at almost any time in the past 40 years.

What is true is the income gap is widening, but that's not the rich getting richer at the expense of the poor, it's everyone getting richer, but the rich are getting richer faster. But that doesn't mean the average person is worse off.