That is presuming these things previously voted on have been implemented or no longer have importance.
Collating Feature Requests in a listing of ones the team is considering to add in future and releasing those votes to be utilized again imho makes sense.
Why even use topic voting? As you mentioned the Likes/reactions could be used instead of being limited to a set number of votes. Using say a particular reaction like 
might be sufficient to gusge interest in a particular Feature request as you could use a data explorer script in this category to return top topics maybe in the Op post with most of this particular reaction.
Vs limiting voting that really doesn’t feel like it is going anywhere as there is not in my experience any updates directly related to this category. There might be from. Time to time and i just haven’t noticed it maybe.
I am sure some of the new things rolled out may have been a feature request at one time though.
Imho topic voting might be better for Contests voting on the top X Topics with a set close date to announce day top 3 winners. But used in this category it feels more like a contest without a clear conclusion with needing to second guess ones votes.