Tracing the history of those various competitors is really interesting. Some (Transmeta) failed completely in a relatively straightforward manner and just disappeared. At the opposite end of the spectrum, NexGen became AMD's future when AMD's in-house design was a flop. Parts of Cyrix ended up with VIA and parts with AMD. Almost all of the big semiconductor companies either owned one of these x86 design firms for a time, or sold those chips under license.
In the 90s, that's actually what happened.
https://en.wikipedia.org/wiki/List_of_x86_manufacturers