They have gotten better and I think it's clear they'll continue to get better :). FSRS is already good (I use it both in Anki and for periplus.app), but looking at the benchmarks [1] there's a lot of room left for improvement.
One direction could be to incorporate semantics, which afair FSRS doesn't do at all yet. A good flashcard deck will have a lot of semantic overlap, e.g., a card for the vocab word itself, that word in a sentence, etc. Struggling with one component is a strong signal you'll struggle with another.
The same thing could be done for just better spacing, so you don't "cheat" by having too closely-related cards next to eachother in a review (the review signal will be less noisy).
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