Because its so slow to extract alot of time and heat is necessary and as it absorbs the dissolution rates slow. Youll never be able to get it fully saturated.
If you have the means, a simple qwiso or qwet can be used to extract the majority. This hash oil can then be decarbed over a double boil. While decarbing it releases co2/h20 bubbles. Watching for the bubbles to slow lets you decarb without heating too much. Thats the cause for most butter and edibles to become more sedative. You preserve the cannabinoids in this way and retain more goodies
While allowing the highest concentration in the glycerin