most Cayman instructors (I was one for 5 years as well) did 600-800 dives a year. The instrs on the smaller ops generally did on the higher end, hardly ever would one exceed 1000 dives a year.
To do 10,000 dives as a Full time resort instructor on average would take approx 9-12+ years. We can name the people that have done that Trace.
Even with your unusual keys experience doing 2 days a day and teaching on days off, you would get approx a dozen dives a week, maybe a bit more. That is about 600-650 dives a year so would take over 15 years to get 10k dives
Anybody who had a position managing in a resort busy dive environment..well in truth you could cut the amount of diving in half to as much as 75% versus the dive instructors/boat DM's. Yet I see often those people claiming they did as much diving as a non management resort instructor. Never saw that happen in real life, even among people like you and I that actually like diving more than most resort instructors..who all love it.
Again, most people claiming 10k+ dives are full of crap. I see shop owners that claim it in the US... big name instructors that never actually worked in the high volume resort environment (but some have books..so they must be special eh?). One person I watched as he updated his resume every year online go from claiming just over 1000 dives to claiming over 10,000 in about 6 years..(must not have known about the wayback website) while posting his non dive vacations, travel, training programs taught etc. on social media. When somebody is claiming numbers like that, even a few weekends off diving, a couple weeks travel time and stuff like a cold can make the math mean that they were doing 6-8 dives a day for their claim to be true. We both know that isn't and didn't happen. Yes, I have done a few days with more than 5 dives,it isn't something you can maintain day on day or even more than the very rare day indeed
But, very few will call others out at that (our) level because..then scrutiny may fall back on them and they may be found wanting with their own skeletons
Nobody wants a honest account, not even the customers who like being able to say "I took a class from so and so, who has over 10k dives, is the author of books, designs equipment, is a training director for some agency etc." because it makes them look somehow more "special" even when as is often the case, the class was horrid.