>Any biopic of her is going to be hard to watch and if it tries to be a happy movie, it is not an accurate biopic at that point

The main problem is that Blonde is hard to watch to the point of exploitation and also still inaccurate. The issues with Marilyn's life you mention are interesting and could have made for a good movie, but Blonde only includes some of them, and in twisted ways. Also while I'm almost 100% certain the creators intended the opposite, part of the movie feels unsympathetic to Marilyn, and even sometimes paints her in the stupid, hysterical light her detractors/abusers forced onto her image.

Beautifully shot though, I wish the same visual talent had been used for almost any other film.

I try not to think too hard about ratings because I think they're generally more useful as a conversation-starter than a hard set point, but on a five star scale it's vaguely...

1 or less - Incoherent. Either no effort went into the project, or those working on it just lacked the technical knowledge to make anything work

2 or less - Clear artistic intent, but a still-obvious lack of competency. Conversely, technically competent but soulless or ill-considered

3 or less - Average overall. Worth watching, but lacks characteristics to really distinguish itself from others, or has strong/interesting ideas, but ultimately fails to deliver

4 or less - All the marks of a well-made film, and interesting enough to really remember. Anything 4 or above I'd be happy to rewatch or recommend practically anywhere, anytime.

5 or less - Outstanding in all or most aspects, always worth watching. I generally think that the difference between a 4 and a 5 is really just personal resonance, as anything above a 4 should be overall already be technically and artistically sound.