I’m not much of a maven either but there are thermometers with over 10k reviews too.
There’s a fire hd tablet with over 100k.
This is around for 6 months. The review count is pretty high for that, but not crazy. If it was airpods or galaxy buds I wouldn't blink.
I would say lots of fake reviews, but very good fakes. The seller did a quality job. I'm guessing all of his fake reviews are from actual purchases, that he was patient at the time gap between purchasing and reviewing to keep the review to purchase ratio within acceptable levels and avoid triggering algorithm, that he increased reviews consistently and gradually (there are a few "steps" instead of consistent slope in keepa chart of review count history, but overall it's pretty smooth, with a few lazy nights that he posted more than he should have), and that he focused on actually promoting item on social media and deal sites instead of exclusively focusing on manipulating Amazon ranking and hoping the customers will come on their own just from being on top of search results. He got a B on Fakespot, which is excellent.
If it's real it's pretty impressive, and if it's fake it's even more impressive. Overall, props to this seller. He seems have model down pat. Slow and steady and not taking egregious shortcuts wins the race, especially when you're cheating and trying not to get caught.