Personally, I don’t think the responsive features Editor X has will make it to Classic. Classic is still missing tablet mode all the resizing features, element sizing options (like setting a button to fill to the size of the container), etc. There is still a good reason to use Editor X however I wish they just made a complete duplicate of Classic and added these features or just added it to the classic builder and kept it all in one tool.
I think the separate development tracks are causing problems and eventually no matter how much the classic builder has, it will become obsolete. Classic is just simply not responsive. The fact we cant zoom in or change browser size without it switching to tablet or mobile immediately puts all Wix sites under Squarespace, Shopify, and WordPress sites. Responsiveness is expected now so I don’t really like building on Classic anymore even though we are missing a bunch of features from it.