The messaging could have been clearer but I'll spell it out for the dumb.

Phase 1:

Don't panic buy medical supplies expecting them to protect you. We don't have enough, and frontline healthcare workers need them to protect themselves and others, you don't know how to wear them and they probably don't fit you properly.

Phase 2:

We still don't really have enough medical grade masks but just fyi: any sort of mouth covering will reduce the risk of a contagious person sneezing into the mouth of a vulnerable person. If you have to go out, please wear something over your face. Cotton is better than nothing.

Phase 3:

A tight fitting mask really is best, it limits a contagious person's generation of aerosolized clouds of viruses, and limits a vulnerable person's exposure to clouds of aerosolized viruses.

IIRC, that initial “don’t use surgical masks” statement was because hospitals were already facing shortages, and a rush on the supply would have caused massive widespread longstanding shortages. Basically, the hospitals needed disposable masks, so the CDC told people not to use disposable masks.

But it was also in that brief time period between surgical masks and reusable cloth masks. So the messaging was basically just “don’t use ~~disposable~~ masks” because the “disposable” part was implied because it’s all that was commonly available on the market. Plus cloth masks hadn’t been studied yet. So when cloth masks were proven to work and the CDC started recommending them, the naysayers fell back to that initial messaging from when the cloth masks were unavailable and unproven.

The way I recall it seeing thing unfold and not really following the political stuff at the time:

CDC said that cloth masks don't stop viruses. You need a medical mask for that, but please don't use those because hospitals need them. That was all true.

In other countries, notably South Korea, almost everyone wore masks, and the numbers showed their effectiveness.

So CDC realized that indeed, if everyone wears one, it greatly reduces transmission of the virus. It doesn't have to be perfect to be efficient.