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.