The are a number of differences between Steel & Aluminum.
Most of the fans of steel wheels will tell you if you clobber something & bend the rim ****** you can (try) bend it back.
Steel wheels don't need to polished.
Steel wheels are less expensive.
Aluminum wheels have gotten quite a bit stronger over the years & while I've seen a few get broken it has been under some extreme conditions & the wheel was one of the cheaper things that died.
Aluminum wheels are lighter reducing the the unsprung weight vs. steel, although they a still big differences in the weight of aluminum wheels. By reducing unsprung weight you reduce wear & tear on the suspension, improve braking, acceleration & ride.
Aluminum wheels give you more choices in offset & width, both things that will affect what tires you can run.
Unless your as lazy as me you'll end up polishing the aluminum wheels.
Aluminum wheels are more expensive