It takes way more effort from the user and leads to more people dropping out.

Then make it 0 to 3 or 0 to 1 for all I care. You missed the point, which is: If I want or don’t want feature A doesn’t influence if I want or don’t want feature B, and linking the two distorts the results of the poll.

in the end, the result is the same in Aggregate.

Not if you include the human factor of the decision maker, who can twist “wanted less” into “still wanted a bit” as a justification if they want a certain feature for different reasons than user benefit (like, say, a “privacy friendly” but indeed not at all privacy friendly mechanism to give data to add networks). That doesn’t fly with “0 points”.