There is a simplest and cheapest method to treat insomnia, but 99% of people can't do it.

Reading a book, usually feeling sleepy after 30 to 60 minutes.
Reading is the brain in activity; after a while, it naturally becomes tired.
Most people won't read books. 😂
The more videos you watch, the more excited you become.
Another method is to exercise or do something that makes the body tired,
burning too much energy, so exhausted that you naturally sleep well.