Do other types of rocket engines not need to be in perfect sync?

> eight high-pressure hydrazine engines (which must work in perfect sync)

There's eight for redundancy, it's a fault-tolerant system.

One advantage is that you avoid having to jettison the escape tower which would add some complexity and risk.

Also, the engines are designed for use in space during a normal mission and to be recovered. So in that configuration the crew would still need to be located close to a hydrazine thruster as a part of a normal flight.

The original plan for Crew Dragon was to have it land with rockets like a rocket should, instead of with parachutes. They also wanted to have a design that could also land on Mars. Safety first NASA didn't allow that plan. Not sure if rockets are still powerful enough to do a powered landing coming from orbit. I hope so and that tourists will have the option of returning that way even if NASA astronauts don't.

Looks like someone is recording a video feed broadcast via a projector onto a dark wall with a cellphone or camera. Probably a cellphone from 8yrs ago.