Also consider that more than half of the hits to Japanese aircraft in the Pacific were caused by the use of the top-secret VT radar proximity fuse.
The Japanese predicted they were going against "dumb" timer-based anti-aircraft, which was probably two orders of magnitude less accurate and less effective, where their weak armoring would have been a good approach: if you think it will take 200 shots to bring down your planes, fielding twice as many units that could each be brought down by one lucky direct hit makes great sense. But if it only takes two shots, you need to be able to survive the shrapnel.
The strategy they put in motion in 1942 suddenly became obsolete in 1943, and it was too late to pivot.
* Poor Japanese fighter aircraft design philosophy (weak armoring, no emphasis on pilot survival).
* Poorly trained pilots (all the veteran, experienced pilots are dead because see above).
* Poorly maintained aircraft (insufficient supplies and manpower).
* Insufficient ordnance (insufficient supplies and manpower).
* Insufficient fuel stores (so a one-way sortie out was all they could afford).
* Insufficient food and drink (a pilot going out to kamikaze is one less mouth to feed).
* Fanatical and delusional military brass.