Even if they were, writing cards yourself forces you to engage with the material in a way that's highly conducive to learning it. It makes knowledge gaps more visible and forces you to understand it if you want to have any chance breaking the material down into pieces that make good cards.

The positive effects of SRS rely just as much on the repetition as they do on the creation of the cards. I know that not everyone agrees with this, it's certainly been true for me.

Premade decks might work for language learning, but even then I'd be wary.

Well said, this is the key part for me:

>It makes knowledge gaps more visible

It's the same principle behind teaching others. It's easy to think you understand something until you are forced to communicate it beyond the surface level.

I've been studying Chinese with a premade deck for several years and it's working very well.

Of course, ideally one would want to create cards, but I only can devote around 30 minutes per day. Under that restriction, creating cards is not really an option.

Which deck?

Spoonfed Chinese.

writing your own cards is very tedious.

True, but I suspect that's due to learning being tedious.

Memorization isn't the same as learning. Using a preexisting deck is memorizing someone else's learning.

It gets easier the more you do it. As you become more comfortable with the software as well as develop an intuition for what makes a good card, the effort shrinks dramatically. Not just because I'm faster at creating cards, I also create fewer cards overall.

I started making the cards, noticed a lot of repetition in what I was doing and then started coding solutions to clusters of cards.

I definitely spent way too long on the "making the cards" phase!