Star Wars 77 is a fantastic movie on its own, but I don’t think it would be as worth remembering without The Empire Strikes Back
Yeah, Empire arguably has more continued pop culture relevance than '77 and more of it has joined the general pop culture osmosis we all ingest. Star Wars, for all of its successes, is pretty basic when you get down to it. It does what it does well, but it doesn’t have the ambition of ESB.
I guess the '77 purism is akin to wishing that the Godzilla series was just Gojira '54 and nothing else. It’s excellent on its own, but you’re missing out on good (and pop culture relevant) stuff if you ignore the rest. At the moment, I’m ok with missing out on that.