Unfortunately, the thing about Raid is that it is massively a game of chance. While some of these chances are quite transparent (such as shard pulls), there's a lot of things in the game that are not, and I wish that Plarium did a better job at putting those numbers out.
For example, there's only 30% chance of a 6 star artifact from Dragon 25, and a 13% chance of it being legendary. If it's a boots and you are looking for speed as the primary stat, then you have a 14% chance of that spawning. If you want it to be part of the speed set then that is a 11% chance. All in all, this makes finding a 6 star legendary speed boots from the speed set incrediably small. From an artifact point of view you really have to be mentally ready to assume that you will be doing thousands of runs to find some decent gear.
To me, this is why it is very important to take advantage of the events that are guaranteed. For example, Doom tower each month has a set of guaranteed rewards (shards and chickens), so having a team to complete that is important. Every month there is usually also a fragment/fusion event which nets a gauranteed legendary, so having the resouces for that is also important. This is also the only time that I pull shards, to complete the associated events. It's also when I farm dragon the most.
I find that when you approach the game around the guaranteed events, then it becomes less of a headache for me. The incidental luck from the randomness becomes an unexpected benefit, rather than something that I define my enjoyment from