Quibble: I think you're conflating "remove winner-takes-all" with "less spoiler effect". The first implies (some of) the second, but not vice-versa.

For example, ranked-choice voting would reduce the spoiler effect and allow you vote for your real choice, however it would not (on its own) change that races have a single winner, who eventually "takes all."

This matters because even if it's preferable to have both, ranked-choice is easier to introduce incrementally and with fewer amendments to various constitutions.