have you looked into donut theme? it looks modern to me.
[So modern for you it's just a look donut theme doesn't satisfy all tastes, doesn't use the latest css framworks, it is not optimized, doesn't support structured data!]
as far as development goes ... its a small community driven product, with not many developers to work on it.
[yes that's a fact, but what should we do for other developers to be involved in the project?]
if you want to make a difference you could always hire someone, make the changes to the code and release them to the community.
[this is not how you develop a project]