Lizzie, that clip does not show the true nature of the incident, if you wish to search there are "better"
clips that do.......
Essentially, Hubert, at 170mph, goes off track to the right and hits the right hand barrier, bounces off it and comes back across the track at 90 degrees.
Correa is on the track and suddenly has a car crossing him at 90 degrees, and can do nothing about it.
Correa is doing around 170mph, Hubert has no speed in the same forward vector, all his speed is at 90 degrees to Correa, so its like sitting in a stationary car and being hit at 170mph... result .. the carnage you see.
Even if he had been in a "cage" the resultant "G" forces on his body would be horrendous and probably fatal. Correa probably only survived because his forward "vector" meant that the "G" forces were somewhat reduced...... essentially he slowed down in the same line (very quickly admittedly) but Hubert was "wrenched" through 90 degrees almost instantly.
Racing is dangerous ..... never, ever, forget it ..
RIP, a brave young man.