I am posting this video as I think it is pretty relevant to the amateur/experimental community. Aluminium in some form or another has been the go-to for aerospace projects but one must look at all the pros and cons of a material for its intended purpose to make the best decision. As you will see in the video, stainless steel is quite suited for what SpaceX is hoping to do.
So, I challenge you to think a bit more next time you carry out a material selection process. You may end up back at the tried and true materials but you might also surprise yourself and find others are more suited for your application.
[For those who want more: The plots in the video of the materials are called Ashby plots and are commonly used for material selection, you may recall them from your materials science papers at university. There is software you can buy that displays these graphs and with user inputs allows you to pick the best material for your application.]