4e needed tech to handle the fiddly bits.4e did have a character builder, first an offline program and later an online-only one. Both were excellent and regularly updated while they were being supported.
What 4e did not have was an online tabletop. That was what the project that ended in tragedy was supposed to deliver. 4e did play perfectly fine on a regular tabletop with miniatures though. It is possible that an online tabletop would have made 4e more accessible to gamers without extensive miniatures collections. We will never know if that would have been enough to deliver the kind of profits Hasbro wanted from D&D, but I am skeptical.
A year in 4e got really fiddly because the easy stuff was handled in the 1st set of core books. If 4e was more like Essentials at launch, it could have longer mechanical life, easier tabletop play, and less stress.
But no D&D would ever EVER get the numbers WOTC wanted for 4e outside of licensing the IP to other media. D&D by its nature has a ceiling on the book side.