Also, that line about "Being good is different from being popular." from the other guy was just ridiculous. Obviously that's true, but ratings aren't a measurement of the former, but the latter.
That's a bit harsh. I will of course grant you that popular does also have a connotation of "liking" the thing as well (forgive me, I was a bit tired when writing the original), but I don't think it's the defining feature, it first needs to have numbers behind it. And most people don't even rate what they read, based on totaling the numbers of ratings vs. the numbers of follows, I'd estimate something like on average maybe 5% (out of the 10 manga in the "Popular New Titles" list, the lowest percentage was about 2%, highest was about 8%, with almost all of the others being 4-5%, small sample sure).
FWIW the algorithm for the homepage's "Popular New Titles" list seems fairly simple, at least on surface. They seem to be ordered by the number of follows/bookmarks/whatevers, and in the case of there being an equal number of thousands they secondarily sort by the rating. And then they probably have a time limit that any manga is allowed to be there, since it's "new titles". The list is probably not entirely real time, only updated ever so often, so you can get slight outliers, but that looks to be the basic formula, more or less. Put it this way: When I looked at it, there was one manga with both slightly more follows and a higher rating than the one ahead of it, but they were still on the same number of thousands. There weren't any instances of a 15k follows being behind a 14k follows, etc.
So at the time of writing, we have on places 2-3-4 the following manga (R = rating, B = "bookmarks", since that's what the icon looks like):
2-I'm Not Some Man's Dress-Up-Doll! R8.27 B21,466
3-Giving Love Advice to an Online Friend R8.23 B21,361
4-I, the Only [Divine Sword User] in the World, Was Expelled and Became the Strongest With the Awakened [Divine Sword] R6.28 B21,424
4 has (slightly) more people reading it than 3, but since they're on the same number of thousands the rating difference puts 3 ahead. Ahead of them is Classmate Maid R7.73 B25,401, lower rated than 2 & 3 but more followed than any of them, and after them is Timid Girl ◯◯ Years Later... R8.18 B15,153, more highly rated than 1 and 4 but way less followed.
As a sidenote, I don't quite understand how ratings are a supposed direct indication of popularity rather than how much people liked it, could you explain your meaning with that? This with the caveat that I can understand high ratings being given to something many people would consider to be garbage. Is it about that side of things?
I promise you I'm not being facetious, in my mind it's just that "popularity" is primarily a numbers game and "ratings" are a perceived quality game, especially when discussing media products rather than for example popular people, solutions or misconceptions. A movie that made a billion in the box office was clearly a VERY "popular choice" for movie goers, even if it was utter crap quality wise (e.g. The Rise of The Skywalker, 7th in box office earnings in 2019), while a movie that is almost universally praised by everyone who has seen it, but struggled to gain any viewers in the theaters, (e.g. The Shawshank Redemption, 95th in box office in 1994), was of high quality, but not popular.
Basically, a lot of people seem to be fine with easily digestible crap quality stuff, so a lot of low rated stuff can still end up being popular.