First of all, LW has never come out and said that's the way audience engagement was calculated. You seem to be making assumptions, here.
Second, I believe the point that OneHappyDay was trying to make is, is that a logical way to estimate a comic's success? Obviously not. A comic with, as One said, 10 views and 10 likes would have a 100% score – that doesn't mean that the comic is a good fit for the Webtoon audience, and that doesn't mean that it should be viewed as 'above' a comic with a higher subscription count.
A series with 200k subs obviously isn't going to get 200k likes per chapter. A comic with 25 subs may, however, get 25 likes per chapter. Yes, those ratios can be mathematically found, but they mean nothing: they neither determine a comic's success nor accurately estimate an audience's interest.