I wanted some control over my Beamer slides, so I started reading about how to create a Beamer theme from scratch. However, in the process of doing so I discovered Metropolis, which I regard as a higher-level Beamer package that exposes certain customization level in a simple and well documented interface. It definitely does not provide the same flexibility and level of customization one can achieve by designing a template from scratch, but it is unquestionably much easier to obtain personalized (and beautiful!) slides using this package.
Motivated by this, I wanted to collect a list of other "higher-level" packages that enable a reasonable level of customization while having good documentation. It is my impression (and this is supported by a quick online search) that Metropolis is really the only one of this kind, but I would like to ask this community for more pointers in case they exist.
EDIT:
I found the following so far: