They were the only high current silicon transistor once, that's why they were popular, not because they
are actually very good (!) - for instance 3A in for 15A out is pretty horrible, and its not much faster
than a darlington of the same period.
If you want a good audio amp transistor these days the comp. pair NJW3281G/NJW1302G are a
good choice, very little gain droop at high current, more than 10 times the bandwidth of the 2N3055/2N2955
pair, much higher max voltage.
Of course it is class-D amplification, you're back to switching devices and MOSFET rule.