An aluminum frame that copies a steel design for aesthetics such as a cantilever cruiser, I can see as being flawed as little concession was made to utilize the materials differing attributes - steel is
more flexible, yet rigidity isn't inherently bad, that debate - which is "better" for bicycle frames, is one that's raged on w/o resolution for quite some time with no sign of ending, particularly if you include composites.
I would hazard that it's not so much the material, but it's actual quality and the engineering behind it's use, the "strongest" alloy in the world won't make up for oversights in those areas - even the engineering "oversights" that may well not be accidental as the strongest, most rigid materials are most often used with bikes that are also designed to be as light as possible - and it's that sacrifice, integrity vs weight, that has resulted in many a failure, far more so than can be attributed to the material alone.
You don't see aluminum motorcycle frames around do you? There is a reason for that.
In fact, not only are aluminum motorcycle frames commonplace, the disagreement over which is "better" is so long-standing as to be almost a cliche, with the Japanese preferring the twin spar aluminum frames for their superbikes with Ducati being one of the few stalwarts holding out with the more traditional steel...
In the end I suspect more than anything it's important to go with something you
prefer and feel safe with, ensuring only that the quality of manufacture is up to the demands of the materials used *shrug* the least expensive box store bicycles aren't usually the best examples of material utilization, engineering & design lol