One of the best orthodox Windows file managers is open source – OpenSalamander

I wish Microsoft would spend some time optimizing Explorer. I don't know why, but it seems like what should be one of the simplest applications (one which has existed for nearly 30 years) crashes so frequently for me and also occasionally has a really long startup time. They did add some QOL improvements (such as tabs), but what I really want from explorer is instant startup and response time