I found a figure that said it took 30,000 years for the first microbes to start showing back up again. That feels weird. Why did the article say that the climate would be returned to normal after 10ish years but it still took 30,000 years for microbe life to return?

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I think you're misinterpreting the article. It mentions that it took a long time for life to come back in the area adjacent or in the crater formed by the impact. That's to be expected, as that area was essentially sterilized by the impact

That that's not what would have happened all over the Earth. If *ALL* the microbes had died, all life would have also died. But we know it didn't. We know that plenty of animals survived the impact and the subsequent climate upheaval. After all, if they hadn't, we wouldn't exist!

So yeah, 10 years sounds like a reasonable figure for the soot and other debris launched into the stratosphere to fall out, and while 30,000 years sounds like a lot of time for life to return to the area of crater, I wouldn't dismiss it out of hand.