The word "effects" has a long and storied history in programming language theory that predates algebraic effects/handlers by decades. The study of effect systems includes algebraic effects but also monads and other type and effect systems. In some situations the lines between these are blurred, for example with "extensible effects" which are algebraic effects implemented by a free(r) monad combined with "data types a la carte"-style open unions.

The simplest example is the continuation effect. It's not immediately clear why this effect isn't algebraic (it's not even immediately clear what "algebraic" means) but suffice to say continuations are very weird and behave very differently from other effects.

At the same time, they're very useful and are a useful part of someone's programming vocabulary.

Because a news site is only for "typical" things?