They've improved a lot, it's mostly the broadcom graphics firmware that still requires blobs. Probably because they've licensed the IP from somewhere else and the effort to reward ratio is too low.
In other words: yes, the firmware is still closed source.
They do seem to be experimenting with RISC-V now at least, the Pi 6 might be completely open when it launches in probably a decade or something like that.
I wouldn't mind them not using open firmware as much if we had unofficial alternatives that worked without sacrificing functionality, but I don't think anyone has managed that even after all this time.