Not sure if I get your question completely. I am also just using blender since blender 2.8ff and I don’t know all the “historical” reasons why it grew that way. But there is a bmesh, its not wingedge but sort of like that ( would have to take a look if you want to know what exactly it is). That is the datastructure underneath that gets built to be able to answer topological queries. This object mode forward backward thing is the moment when the structure gets synced with the simpler mesh respresentation.