Best place in the world to spearfish. Simple vote

The Great Barrier Reef is a mecca for underwater adventurers, offering an incredible diversity of marine life and extensive reef systems. The crystal-clear waters provide excellent visibility, allowing spearfishers to spot their targets easily. The reef's protected status also ensures the sustainability of its fish populations.

I do drive all over the world I just recently got back from the Philippines and Thailand and now I'm in Korea.
I find Oahu Hawaii to be extremely fished out which is probably why somebody said you have to dive 100 ft in Hawaii, but I liked Molokai much better and found there were a lot more fish there.

Mexico, just south the Puerto vallarta, was pretty good.
But I would say my favorite would probably be some of the islands around Phuket Thailand.
Of all the above places the Philippines and Thailand you don't need a wetsuit, although I wish I had one for protection carrying it and the extra weight it entails there's a bit of a burden so I usually don't bring one when I go to those two countries.