I believe SRS is overused. The spacing effect is, of course, real and quite important. However, it lends itself to decontextualizing what you're learning.

For example, foreign language vocabulary is best learned in context (ie., in sentences, within conversations). That's the only way to know how it's actually used. Otherwise, you're just learning a mapping between first and second languages.

There are other benefits to learning in context, as well. It's more fun, sustains long-term interest better, and these emotional benefits enhance memory as well.

Most interestingly, there are efficiencies to learning in context. For example, one can learn two new words in one sentence.

For all these reasons, I believe it's quite unfortunate that the first language learning tool everyone grabs is some kind of SRS flashcard system. And similar arguments apply in other domains.