I'm a full time professional musician. I make my living teaching and gigging. The gigs are of course all cancelled. Much of the teaching I do is with large community bands, and so that has also stopped. However, I've been able to transition some one on one students to online lessons. The income I make from that is far less than $2000/mo, however making any money disqualifies me from CERB. Had I known that, I would have been better off not attempting to salvage any income. We're actually losing by trying to adapt to the situation and help ourselves slightly.
Beyond my own case, it absolutely does not make sense that someone collecting CERB isn't allowed to earn any money to top it up. It discourages people from working if they can. What if I need $2200 to pay my bills for the month, but I can only find enough work to make $200? With CERB, I can't take that job because I'll lose $2000. It's absolutely crazy! If you're on regular EI you're allowed to work! (https://www.canada.ca/en/services/benefits/ei/ei-regular-benefit/while-receiving.html) They already have a system worked out that makes some sense. Why should freelancers have it so much harder than regular workers?