Many people were working these jobs without realising what a bad deal it was. They were kicked out during the pandemic and learned that any other job is better.

The only thing that was keeping this jobs in place is imperfect knowledge. Most job seekers have a limited knowledge as only know their own past jobs and the ones from close people (and to talk about pay is quite taboo in many countries). And that is how we got here. Even when there is public information, many people have a hard time understanding the implications of the statistics and concrete job differences.

Corporations have thousands of data points and share salary statistics between them.

Staying at home and even firings have helped some people to gain that knowledge.