The Big-3 Celtics are not a good analogy because they were an oooold team. In 2008, Pierce was 30, Garnett 31, Allen 32. They really had a 3-year window.The road for Cleveland was very easy, no doubt. They have only beaten one very good/great team in the last two playoffs as well. I just don't see anyone arguing that this Cleveland team is historically great, so the bar is different.
If Golden State comes out and wins another couple championships than they are in the discussion. Right now their resume looks much more big-3 Celtics than Jordan's Bulls.
The Warriors are still young. Curry is 27, Thompson and Green 25, Barnes 23. The supporting cast is older (Bogut, Iguodala, Livingston are all 30-32), but the core is young. I'm not sure Curry can improve much at this point (at least in the regular season), but Thompson, Green, and Barnes should all be expected to get better next year.