I think being a chameleon is overweighed in how we value actors. I think it's a great skill, but it doesn't place one necessarily above other actors who doesn't possess that ability.
What I find with chameleon-like actors (Meh, Cate, DDL) is that they can also be overly mannered and hammy. Their technical skills are so superior, it's at the expense of freshness and rawness that we see in other performances from non-chameleon-like actors--which I think Frances McDormand possesses. So, her performances may "blend," but there is a realism to her some of characterisations that I don't find find in the more mannered, chameleon-like actors.
Pauline Kael wasn't a big fan of Meryl. It's been decades since I read her reviews, but I think she made a comparison between Streep and Winger sometime back around Officer and a Gentleman and Sophie's Choice. I think she articulated better what I'm trying to say, but it was something to the effect of being able to watch all the mechanisms inside of Streep's head move and that her performances were so pre-determined and automaton-like. With Winger, there was surprise and a rawness that was exciting and had a spark. While I think Kael was overly harsh when it came to Streep, I do think she had a point.
And I do think when the average person thinks of great acting, they tend to go to the more technically-capable actors over the ones that are more dynamic and less refined.
At any rate, McDormand's Dot in Raising Arizona is comic genius. She takes a one-dimensional character and seemingly gives a one-dimensional comedic performance, but if you look closer, there is an underlining tension and mistrustfulness that works so well after we don't see her again and her husband does all of her bidding. And, of course, it's much different from her comedic turn as Marge Gunderson. McDormand might not be a "technical" actor in the sense that she can do a lot of accents, but you can plug her into a lot of different genres, as well as place her characters in various socioeconomic settings, and she plays the roles quite convincingly. I think that's versatile.
People tend to write her off as giving the same performance without familiarising themselves with the breath of work, which I'm thinking about doing now actually.
I did that with Annette Bening. A lot of people write her off as "that actress who can play a shrew" all because of American Beauty. She's another one who isn't known for her accents or ability to be a chameleon. I went through her entire filmography last year, and her range is kind of breathtaking.
