Put simply, you can't have it both ways. The goal of cancel culture is to cancel what people find offensive. You cannot say 'this thing X is not offensive becuase I have decided it isn't... and besides, it's worse when XYZ people do it'.

Some people have presumably found her actions offensive. Providing an argument to the contrary such as, they're racist, sexist or blinded by their fandom has already been voided from validity by numerous proponents of cancel culture. If it has been found to be offensive, she is defacto guilty of a crime against the mass and can be 'cancelled'.

Lizzo will survive, because like Ricky Gervais and other smart celebs waking up to the reality of cancel culture, she either doesn't give a shit, or can adequately pretend not to... this retrograde identity politics fun-bus was always going to go off-road at some point and start consuming itself. For those of us who have been warning about it for (seemingly) forever, the next year or so is going to be interesting and hilarious in equal measure.

Lizzo is just the first in a long line marked 'people who don't really deserve it, but will get it anyway'. The mob is stupid and funny people are low hanging fruit, jokes can be deliberately and wilfully misinterpreted and easily weaponised into offence. This has nothing to do wth racism and sexism and absolutely everything to do with groupthink stupidity.