Rare that your engine would suddenly die but even if it did you’d still have brakes. Some with residual vacuum and then brake, just not power assisted. Think the term e-brake went away when dual master cylinders became the norm. We now have parking brakes.
2006 Gulf Stream Friendship G7
350 Cat, Crusier Lift w/ Honda VTX
Blue Ox and 2019 Chevy Blazer RS AWD V6