Since apparently this needs repeating: how is it that there can be so many people on CERB?

It is because so many people lost work. People need support.

Is there some fraud? Perhaps, but the data suggests it is not widespread.

See this thread on data from the LFS. https://twitter.com/kevinmilligan/status/1258815500961763328

Sometimes, craven politicians make scapegoats of "welfare cheats" to disparage those on public benefits.

Distasteful, but the number of recipients is normally small so the political temptation may be there.

But disparaging 7.5MM Canadians on CERB as "cheats"? That's...bold.