This year's summer COVID surge shows that (predictably) the change in the CDC's isolation guidelines is a disaster. Hearing about so many instances of people returning to work/school unmasked 24 hours after testing positive.
Most people are infectious with COVID for at least 10 days. 24 hours was never going to cut it. And while the CDC did try to mitigate this by adding that you should mask for a few days after returning, predictably no-one is even doing this.