I guess that's your choice, but someone has to buy the series for it to continue, and a lot of stories just can't be told in one book. I recommend looking at the author and their track record for finishing stuff: some writers like GRRM get a bad rap for not finishing their stuff, but that does not reflect on writers who actually sit down and crank out content like Brandon Sanderson. There are writers that actually finish what they start in a timely manner. Though personally I'm not picky about a series having to have a conclusion. Life's a journey, not a destination. The joy in fiction is not where it ends, but in the path that gets there.
It was subtle, but one of the things that put me off reading the GRR Martin (grrrr Martin is about right....) series beyond Book Three, was that each book (after the first one) FELT as if it was nearing the end of the story arc. If I had started reading when he was still writing 'the next book,' I might have stuck with it, thinking the next book would be The End. And yet, having finished Book Three, I looked ahead to discover that there were (at the time) three MORE to wade through—and the series STILL wasn't finished—it began to feel like a soap opera, and I quit. Pity, because the writing itself was good, and the characters and situations were interesting. But a soap-opera-like, never-endum taint was there, and I couldn't shake it.
I see a lot of digital books that are series with a distinct flavor of the series books being really long chapters. In other words, you finish a book but it intentionally leaves you without a sense of completion in an effort to keep you buying the next book in the series. I think that sort of thing is dishonest for one's readers. I'm fine with a series of books with the same characters but believe each book should be able to stand alone. I made it a point in my (two books so far) series to state on the Amazon page that my books are written and can be enjoyed as stand alone pieces. Either volume can be picked up and read individually; the order isn't greatly important though they are better read in sequence of course. There is enough minimal reference to what happened in the preceding novel that a reader won't be lost nor irritated by lots of wasted recap. Series books are very, very popular and a good way for an author to make money once they've found a fan base. Unfortunately too many authors write for the money aspect and not for the respect of their readers.
I'm getting sick of series(-es?) myself. Less with the fact that they're a series, and more with the fact that most of the ones I've read lately could have easily been one book, but was cut up and fluffed into a series because they and cinematic universes seem to be all the rage right now. At times I think it's a sales tactic based around The Sunk Cost Fallacy.
I did not even know that there are authors who seek investments to book series that are not written. That sounds nuts. One book with some kind of common-good agenda... yes... I get it. Entertainment or series of books. That's in the wrong side of a parody horizont. 1. If anyone writes a series that is not stand alone, it's like telling both publisher and audience to f*** off. If those books are good, then first one sells X. Second sells 0.5X, third 0.20X... So... Author has decided that he/she does not want to have large audience. Let's make him/her happy by giving him/her what he/she seeks. 2. Until it's done or at all. I buy myself maybe 60-70 books a year. That eats big bites of the inside of my wallet. If a book is 14€ I really, really think before buying it. If buying a book means that I must buy a whole series, there is absolutely no way I will buy it. If author has done his work well, he/she has found a way to make all books stand alones. If they are not, they are lousy work and I will not put my money to them. And bookstores? They might put the first one visible - if it's good. If the second one is not stand alone, they know it will sell less and sales is not so much dependent about visibility. So... Bottom shelf or storage room for second book. And "you can order this and it will come in less than a week" for third. And publishers know this. And author? Well... To me it's writer until first or second published books and self pub does not count unless it sells well. The difference between writer and author is buying audience. When there is no buying audience, that person is not author but writer. (And to me drafts or scripts are not books. They become books via publishing process, not without that. These are of course opinions, not truths - like almost everything in any writing board.)
