It's great for workflows with clear points in the logic where things should happen and it provides more sophisticated (i.e. powerful but harder to master) tools like Fibers and Streams which allow you to reason about failure cases of reactive asynchronous operations. In many cases it offers a clear path out of callback-hell that is more reliable than promises and async/await.
However while the Effect-ts docs are getting better and may be ok for people with a good knowledge of functional programming and Typescript, they are nowhere near the quality they need to be for those who don't. People looking for examples online will get frustrated because Effect API churn over the past three years has made many old posts and articles obsolete. Old github repos won't work out of the box. And you better be comfortable with codemods if you haven't frozen your Effect-ts version.
Fortunately the Effect-ts Discord channel is full of friendly and helpful people and the Effect team provides high quality assistance to people who ask for it. It makes me sad this treasure trove of information is trapped in Discord where search is of little value.
A good book or collection of high quality examples of how to use Effect-ts with de-facto standard frameworks like React could help its adoption grow significantly.