Primals are derisively called "Red Ancients" for good reason. The un-boosted odds are .5% Mythical, 1% Lego 16% Epic and 82.5% Rare, and Primal Mercy for a Mythical Toon does not kick in until 200 Primals pulled.
On top of that, we typically get 2X Primals only 2-3 times per year.
So, unless you track your Shard pulls, and have an actual count, all you are doing is complaining about Drop Rates that are published in-game, and have been the same since they were introduced.
I track my shard pulls, and it took me 144 Primals to get my first Mythical Pull.
Plarium intentionally keeps the amount of earnable Primals on the low side, so even active players that don't do a lot of Live Arena and/or who aren't in a competitve Clan for Hydra & Siege will not have even pulled their first 200 Primals yet. Some people get mega-lucky, but the rest of us have to play the odds, and the odds always favor the house.
At least once per week, someone goes on the Discord Suggestion Log to say "Get rid of the Rares from Primals", but Plarium has absolutley zero incentive to do that, and if they did, Primals would cost a lot more than $5 apiece, and they'd become a whole lot more difficult to earn than they already are.