It's really good to ask these questions.

I'm not a medial researcher, but my impression is that many fields find it difficult to produce the robust high-level risk comparisons that you ask about. I.e. if you're looking at blood fats, even there you'll find many complicated contextual factors (age, sex, ethnicity, type of lipids i.e. LDL or lp(a) or ...?). The same might be the case for sugar. So it's not really easy/cheap to combine detailed state-of-the-art measurements of different causes into one randomized controlled trial.

As for the effects of sugar, I think there's some evidence that's not too hard to find, e.g. some meta analyses showing something around 10% increase in dose-dependent risk (RR ~ 1.10) [1,2]. A lot of the literature seems to be focused on beverages, e.g. this comparative cross-national study [3].

[1] https://jamanetwork.com/journals/jamainternalmedicine/fullar...

[2] https://www.sciencedirect.com/science/article/abs/pii/S08999...

[3] https://www.nature.com/articles/s41591-024-03345-4