Be aware that you are usually looking at prototypes, not available products. Currently its mostly another set of startups to invest in. They might look attract

Be aware that you are usually looking at prototypes, not available products. Currently its mostly another set of startups to invest in. They might look attractive to VCs because they're ambitious, require lots of capital, and the technical feasability of a specific approach is complex enough to find merits in. The jury is still out if any of them are actually viable from a technology and economic perspective. Lilium's approach specifically has been publicly critized by aviation experts to not be make sense when looking at the basic physics.