it is an usual system to work with. As with OP situation, it is very frustrating that you have so many layers of RNG to play with to get a good item.
I personally prefer systems that have both a long way and a luck way.
The long way guarentee’s what you get for a lot of hours put in and maybe a hard boss to go with it.
The luck way is similar to what we have now with lower chances, or just remove the glyphs and have say 4 chances.
Having two options will cater to the different types of players or even to certain builds that can slowly work there way up.