There were some true transcendent artists at Woodstock (Hendrix, Alvin Lee, Joplin, The Who, Carlos Santana, Crosby-Stills-Nash-Young), there were still more strictly period artists who contributed little more than the sound of the times (Country Joe and the Fish comes immediately to mind*).
Hendrix and Joplin died early. Alvin Lee was a phenomenal guitar player to the end, and contributed widely including to quasi Christian Rock (along with George Harrison, Ronny Wood and others) with Marlon LeFevere.
The Who, Santana, and Neil Young continue to play, but truly to very select audiences.
Pink Floyd managed to transcend all the eras well and without cliche, maintaining new material and new sounds, but all easily classified as "Floyd". Not everyone likes it, but it never lacked attention to detail or performance, in spite of the constant bickering in the band. The Rolling Stones couldn't even do that.
* I have a recording of the 1968 (or 1969) first US set / performance of Led Zeppelin. They opened for Country Joe and The Fish. You can feel the collective gasp of every person in the audience as "Dazed and Confused" winds up, and the collective sigh of Joe McDonald and crew as they see the lights dim on that era.