There aren't really tools they can add that would teach you concepts for how you should play, because once they do they impede the development of their own hard content. They want us to have some difficulty learning the fights, because that's what makes them last. It's also what leads us to have satisfaction when we overcome/learn the mechanic.

A lot of raiders will never admit to it when called out like it's a bad thing, but they use third party tools beyond parsers to hold their hand like this in fights. The rationalization for it usually comes down to, "This mechanic would be unreasonable for me to perceive, so it's OK to use something that tells me when and where it's happening. It's not any different than human callouts." Neverminding the fact that human callouts are subject to time constraints and human error.

Anywho, more on track with the idea proposed in the OP: The idea of a death clip camera wouldn't be able to reliably tell you why you died. Even things like the ACT parser on FFLogs can't reliably do that. It's up to you to read the log and figure out the chain of events. Of course, having an entire time map of second by second, play by play of the fight also helps immensely.

As it stands, in the modern age, most computers and all of the consoles have the ability for you to record your gameplay. On PS4 you can record before you start or record up to the past hour after the fact. You just have to set it up, by default it's the last 15 minutes. Even if you don't upload it somewhere, you still have the ability to go watch the recording whenever you want.

Also, since this kinda thing eats up time, it would be something people have to do of their own initiative after the fight is over, because while there are times where you sit dead for a while, fights go on and people try to raise you. Even if people wanted to review their death, they'd then have to contend with the possibility of missing a raise and causing a wipe anyway.

Also, as far as Hall of the Advanced or Hall of Heroes or whatever nice sounding idea about high end Hall of the Novice goes... they won't ever make it mandatory. Hall of the Novice's only mandatory thing is going there to let them strong suggest that you learn from them.