they all have different target audiences though. The WP market is so vast there’s room for all of them.
Divi carries a lot of technical debt holding it back. But it’s more for non techies and designers building mostly static sites. There’s plenty of demand for that kind of build. Hopefully once 5 is released they can work on more simplifying more complicated, css based builds and removing bloat.
Bricks is more focused on building tools for developers, much like Oxygen.
Elementor is trying to be the easy “all in one solution” for non techies. Ie, they seem to be closing in on Divi.
Breakdance is trying to go for the market between Elementor and Oxygen/Bricks. More sophisticated builds for people who don’t want to buy in to Elementor everything.