Induction Machines are Mechanically simple. But require a AC source which is what commutator in a DC machine is doing. These days however you can use electronics to drive a Induction Motor from a DC source.
Or you can use permanent magnets (cost more) for a classic Brushless DC machine. However the BLDC also required Electronics to run it.
It should be noted that Motors are inherently poly phase AC. ie we do things to DC and single phase AC to mimic this in the physical machine.