It really depends.
Putting on my publisher hat, here's the thing. Let's say that you're pitching me a book. The first question on my mind is "how many copies can I sell?" If you can tell me "I've got this series and every time I put out a new chapter, I get 500 views and 100 likes, and I've got 250 subscribers," then I now know that you've developed a following. So, if they'll follow you on this journey, there's a good chance that they'll follow you on the next one. And if they like your work, then there's a good chance that others will too. So, I've now got a good reason to put in the time and resources needed to develop your next book (which, for a fully publicized release, can be thousands of dollars). The odds of a good return on investment are high.
On the other hand, if you come to me with this argument and say "Would you like to publish the serial I'm releasing right now," my answer is almost certainly going to be "no." First, all of these people are getting to read this for free, so the only way that I'm going to be able to sell books to your existing readers is if there's enough value added in the print and e-book editions that they think it's worth their time to read it (aka, new content). Second, since any new readers will be able to find your serial online, I'll only get a fraction of those readers too. Now, if you could say, "I self published, and here are the numbers of books I moved in comparison to views," then it's a different discussion, but that's not something you're likely to have as an option.
Now, since I am actually going to be selling copies of my serial, some clarification is necessary. There is a big difference between taking a risk and doing something experimental with my own work, and taking a risk and running an experiment with somebody else's, particularly when I'm personally trying to build an audience and resurrect my fiction career in the long term (I found myself on the wrong side of the Lord of the Rings glut back in the early aughts). And, there are two more volumes of Re:Apotheosis stories coming - only one story from the second will be serialized, and the third probably won't be serialized at all. So, there's a long game that I can afford to play with my own work that I can't play with somebody else's.
But, that's the decision making process from the publisher's point of view.
