There is plenty of evidence Fructose is the key killer ingredient in our diet. It causes diabetes, cardio vascular diseases, liver diseases and when combined with fat it causes alzheimers disease.
Now here’s the kicker, soylent and many clones put fructose in form of isomaltulose in the formula in high amounts. Isomaltulose metabilizes to fructose in same amounts as table sugar only slower, and still is half fructose half glucose.
More to point isomaltulose has some features that are better than sugar but overall it is almost as bad as adding sucrose for chronic diseases.
Sugar->how fructose is bad for you. Note its about fructose in your liver, and after liver that causes problems, and not about the form it enters in the mouth.
How replacing sugar with iso-maltulose isn’t much better. Note it is comparing to sugar, and sugar is really bad, so not clinically significant difference means it is almost as bad as adding sugar.
The trade off is of course the taste, you cannot make anything both really healthy and taste sweet. I personally got completely rid of fructose temporarily last year and for a while my taste preferences changed so that consuming sweets became hard, I failed badly at new years eve on the diet and didn’t get back although somewhat limited my sugar consumption still.
I think soylent is better than many of processed food at grocery store which add sugar to it in higher amounts and you can easily exceed the amount of sugar you get from Soylent. But if you really think about getting rid of sugars and put your thought to it you can do much better than current formula of Soylent that is close enough of average stuff.