This is an interesting read and tbh I don't have any set answers for your questions - when I started getting high engagement some said it is just a vanity metric - but I beg to differ - I am not writing merely for the views or earnings for that matter - I love the interaction and a lively comments section is always good in my opinion -

Medium is an engagement platform and what most people don't realize is that it takes claps to trigger the algo - it is also great to support other writers and if they reciprocate then win win