Cutting caffeine after 2pm fixed my sleep better than any supplement

I've spent stupid money on magnesium, ashwagandha, ZMA, melatonin gummies from a popular online brand, all of it. Marginal gains at best. Then I just stopped having pre-workout for evening sessions and stopped the 4pm filter coffee. Within a week I'm asleep by 11:30 and not waking up at 3am. Same training, same food. Not saying supplements are useless. Just that I should've fixed the obvious thing first before buying a solution. Anyone else find the boring fix worked better than the expensive one?