EDIT: Myopic cat beat me to it, but I think we agree.
Let's talk about motive first.
For gameplay the only reason to remove randomness would be to make it more normalized and to avoid those unpleasant cases of getting bad hands or repeated cards when you don't want them. Making the randomness more clumpy would only make the game experience worse and would serve no purpose. It's not like people flock to the store to purchase more gems after a run of bad luck.
It's actually a similar situation for opening cards. You might think that modifying the RNG for opening packs so that people get more repeats would make more money and that would be a reason to do it, but that is the opposite of what usually happens. Most companies (EA too in other games) make it so that after after opening a certain amount of packs you are guaranteed to get a higher rarity card. Opening these cards is what makes people feel addicted to purchasing and opening more packs. Getting a bad run of repeats actually generally discourages purchasing and that's why companies try to avoid this. So basically, modifying the RNG to be worse would just make the game make less money, so there is no reason to do it.
Even beyond a motive, implementing algorithms that are very close to true randomness is very easy, so technical difficulties would certainly not be a reason.
In my experience, seeing clumps and repeated instances is exactly how randomness works truly works, it just that our minds like to remember the cases when we see clumps and feel that something truly random should be normalized (no clumps). I bet that if you calculate the probability of getting a dupe and start taking notes of every single card you draw or swap or open, you'll find that after a long enough sample size that it is close enough to the expected variance.
You may be surprised to hear this but most online CCGs have people mentioning that they find the randomness questionable, MTGO is a particular outstanding example. But I can probably point to at least one forum post like this one for every single online CCG I've played.
