If it was a universal stimulus that's be great, but that 10% is a hundred-million-dollar subsidy to dishonest people and outright fraudsters. Such incentives affect people's behaviour and over long term this might even accumulate to a pretty damaging change in culture that will be very hard to fix.

Some people like to complain about regular welfare programs being abused, but at least those have some controls, they're not just a web form with your bank details. Abuse rates will surely be much much higher for CERB, and that was largely preventable.

I’m ok with it - it allowed many of my friends to survive the pandemic with out too much fuss and any controls put it to prevent abuse would have delayed much needed help

This is correct.

My wife works as a professional in the field. She says outright and obvious fraud is criminal code territory, and simple dishonesty (like what most amateurs do, just lying to a government official because they think they can get away with it this week and next week doesn't exist) just gets you a permanent denial of any future payments. That means you're cut off from welfare, for example.