Keep in mind the pool of total champs is constantly growing, which means the odds of getting a specific champ naturally go down.
I started recently, but I've noticed a lot of the older accounts/youtube vids/tutorials talk about meta champs that have been around forever, so when people got them 2 years ago they were really common since the total pool was smaller.
My newbie advice would be to not worry about the meta champs and look at what you do have. You're filling roles for most of your teams, and there's a lot of champs (rare, epic, even some common) that can fill those roles. The game is figuring out the puzzle with the peices you've been given. Not waiting to pull the same 4-5 champs you constantly see in all of the tutorials and in the arena so you can copy someone elses work.
For example, there's only a few champs you can use for an unkillable CB team. I don't have any of those champs, good chance I might never have them, so unkillable CB team isn't on my to do list. I gotta solve that puzzle some other way. On the other hand, I have a paragon, but still can't get it to work properly on the spider 17-20 cheese, so plenty to do!
There are a lot of champs in the arena I avoid like the plague because I know I can't beat them, but I also run into full lego teams I'll wipe with a full epic team all day long because I know they have zero synergy. Four super powerful legendaries that aren't filling all the roles are useless to you, so figure out what you need and then do some research on what you have.
I spend a lot of time on ayumilove's pages of aura's/buffs/debuff's seeing what champs I have with those specific skills I need. I needed to place a heal reduction debuff on someone recently for a challenge and it was easy to find a champ on my roster that could do the required debuff and throw them in some gear and put them to use by looking at those lists. I was able to take my paragon in, instead of waiting to someday pull queen eva or ma'shalled or some other lego I'll probably never have access to, so don't get caught up thinking you need specific champs.