Large parts of the country have been handed back over to the Taliban for years. I just read an article an article from 2017 talking about daily life in a Taliban controlled region. The American government has known exactly what was going to happen for years, but had no remaining political will to continue occupying the country. There was also no political will in Afghanistan to continue the "western style" government the Americans has put in place without the continued support and payments from the US. This is just the final step in a years long surrendering process.