I also wanted to add that not Marx, Engels, Lenin, Stalin, nor Mao came up with dialectical materialism. It was actually a guy called Dietzgen. No one reads him anymore but you can if you want. Lenin and Stalin quote him heavily since he’s the first one to actually use the term.

You may also see similar things outside of Marxism which look quite a bit like dialectics. Structuralism does something really similar with it’s “inverses” concept. I’m not a fan of dialectics since it feels a bit too idealist for me. Mechanical Materialism is more my style but it’s nothing worth fighting over.