To be fair, if you're an established star and the studio/director aren't going to push the issue... why put all that effort in?
Thom Cruise playing Jack Reacher in a movie comes up all the time in this type of debate. Sure, Cruise could have passed on it and said that it would be ridiculous for him to take that role... but, they offered him a ton of money (anywhere from $12-20 million) and didn't require him to grow a foot taller and put on a bunch of muscle. Plus, it's not like one flop is going to derail your career at that point, you're Thom Cruise and you've got multiple other, better, projects in the middle of shooting. Take the cash and never look back.
I blame Marv Films and Apple (who paid $200 million to buy that turd of a movie) for Argylle more than Bryce Dallas Howard. If you're BDH, why wouldn't you take the payday if they weren't going to force the issue on you losing weight and looking the part you're playing?
It's 100% on Apple/Marv for not saying, "if you don't lose weight and look like the character, we'll get someone who will" and move on from her. (which is what I'm guessing Nolan said to Damon when he offered him the role... "it's yours if you want it, but... you gotta agree to put the work in. If you won't, we'll go grab Ethan Hawke"
