Netflix doesn't actually cancel more series than other platforms do - the difference is that we watch Netflix and get way more angry when we lose a show there. But I get that it's become frustrating. The thing is, they use metrics that are pretty different from what we'd imagine. It's not just total viewership - it's production cost versus how many minutes people actually watch, how long it takes to recover the investment, whether the series attracts new subscribers or just keeps the current ones. A series that has a small but super engaged fandom might be less profitable for them than one with more scattered views.
There's also the dynamic where something new is always more attractive to the platform than continuing to fund an existing series. When you cancel a series after 2 or 3 seasons, that budget goes to 10 different pilots, because theoretically a new hit could generate more buzz. It's a pretty risky and frustrating model for people who love following a story at their own pace, but it makes financial sense to them - at least that's what they believe. The problem is that this created a generation of series with no decent endings, so naturally people get mad about it.