By "bryophitic", I mean "non-vascular land plants", being the liverworts and the mosses. (Hornworts are comparative latecomers, so we won't be talking about them.) Without vascular tissues, these plants can't grow big or far from water or any kind of damp soil.
But that's just on land. In an alternate Earth, a long-ago mass extinction event (say, Jurassic-Cretaceous), nearly drove the mosses and liverworts into extinction. They survived primarily by seeking safety beneath the surface (in layman's terms, underwater.) Would being totally submerged in sunlit water, first fresh and then sea, allow them to grow into forests, or would their lack of specialized tissues just make meadows and prairies out of them?