Firstly, I would never force anyone to do anything they don't want to do or see value in. Different things work for different people and it is important meet people where they are and allow clients to work through things their own unique way.
Also, this is actually a much bigger question than it seems, and it will take some exploration during our sessions to come to any meaningful conclusions.
While I can't offer a concrete answer as to why it didn't work for you personally, I can say that intention is often at the heart of the issue. Many people practice different breathwork/ mindfulness techniques WITH THE INTENTION TO SLEEP and when they don't get immediate results, they decide it doesn't work or maybe they keep practicing (struggling) using these practices to try and force sleep. In time these practices actually become correlated in the mind with insomnia and doing them in this way can make insomnia worse.
As you will learn, when it comes to insomnia, intention is of vital importance. All relaxation techniques should only be practiced with the intention to relax, which is a long-term strategy akin to weight lifting to build muscle. Trying to use them as anything else limits their effectiveness and can lead to increased insomnia.