Sharing from my personal experience — with the Typelevel libraries, you don't really need monad transformers if you don't like them.
For dependency injection, personally, while being a big fan and contributor of Typelevel, I prefer to use Scala as an OOP language, too, as OOP is already great for dependency injection. And I'm always surprised by the lengths people go to avoid passing parameters to constructors or to functions. Although I will say that the use of Resource for managing the lifecycle of resources is a Scala super-power.
For errors, there are different approaches, no one size fits all, but personally, I never use EitherT or OptionT, and that's a false choice being presented by these 2 communities. You don't have to pick between EitherT or ZIO because you can choose neither.
Domain / input errors have to be designed with care, and you usually don't need short-circuiting for those. And as an alternative, what you can do instead is to design errors out of existence. I'm sharing some design advice for that here: https://alexn.org/blog/2022/04/18/scala-oop-design-sample/
The
lemmy.mlinstance has some controversies regarding its maintainers, which may have an impact on adopters.programming.devseems safer for now, for programming communities; I just hope that it's a well-maintained instance.