While that was cool, I'm not sure what the purpose of the exercise was. Was it to test the side boosters while in space or while here on Earth? Also, was the intent to blow it up or did the rocket come in too hot during landing?
This is going to be a drunken word salad... fair warning.
We currently have the dragon capsule that sits on top of the falcon 9 rocket. This can carry 7 astronauts to the ISS and can only dock to the ISS or orbit the Earth and come back. It rides on top of the Falcon rocket that can land itself, but the dragon capsule still touches down with chutes.
What we saw tested was SN8, the 8th iteration of "Starship". Starship will sit on top of the "super heavy" rocket.
This capsule, unlike dragon, can land itself like the Falcon 9 rocket. The Starship will be able to carry (allegedly) 100 passengers at a time. This is the craft (or an evolution of it) that will be used to colonize the solar system. The idea is to be able to land this thing on Mars, Europa, the moon... wherever. What's cool is we can in theory retrofit a bunch like condos, land them upright on Mars, and launch a follow up Starship full of passengers that can live in the ones we previously sent. It will have a massive payload that can be used from ferrying 100 passengers at a time to being used as a refueling station in space.
Comparison for scale:
Take a look at the falcon heavy. That's basically what I posted above, just with three boosters instead of one.
You can see how big starship is in comparison to everything else. Because of its mass, its landing isn't the same as the Falcon 9 boosters we are accustomed to seeing. There's an entirely difference approach and reentry "dance" if you will. It's been labelled the "belly flop", where the Starhip free falls back to Earth. It's followed by a rather violent "pendulum-like" swing as the rocket attempts to become perpendicular to the Earth instead of parallel like it is in the belly flop. This is actually pushing some pretty crazy physics when you consider the scale. This test of the SN8 was to primarily test that belly flop bit, and everything else was secondary. Landing wasn't really a checkbox they were trying to check off. They do that regularly. It's easy. The goal was to belly flop and hit the pad, and they freaking nailed it.