to my knowledge not yet. you sort of have to build your own feed by asking for or otherwise finding other peoples pubkeys and channelID's if you are using Anigma for example.

but on astral.ninja there is a global tab where you can see everything afaik. astral.ninja is a bit slow tho, but very userfriendly, but a bit slow.

you can click the search tab to see global activity. From there you can follow people you find interesting.

more-speech (github.com/unclebob/more-speech) allows you to create tabs with different follow/block lists. One of those tabs is "all" which shows you everything.