What is the point of journals nowadays?
The primary reasons for the continuation of academic journals are correlaries to some of the things you've mentioned as negative. 


Peer review. This a key driver for academic publishing in general. It provides a way to control the quality of published material, and an enforcement of accepted standards, and (for the author) feedback prior to publication. 
Communication. Journals provide a means of communicating research to a targeted audience. Conventional subscription-based models do so for a fee, while the rapidly growing open-access model (which I highly commend) provides even broader and easier access for researchers, students, and others. 


In short, journals serve to curate content to meet the needs of a particular audience, and thus they are unlikely to completely disappear in the near future.