Have you actually played either of those games? Or 2K at any length?
I can't fathom how you can compare 2K unlocks with those in other games that aren't made artificially difficult to boost microtransactions.
Unlocks happen naturally and quickly in normal play in GTA and MGS1. This applies to almost everything in those games. A FEW items take a bit of extra effort but they're usually a few prestige items for completing the game repeatedly on different levels, which is actually a fun objective in and of itself. It's a reward that says, okay, you're a badass. Have a bandana.
It does not take SIX TO TEN HOURS of repetitive gameplay for ONE COSMETIC ITEM in these games, and your progress IS NOT STALLED if you choose to grind to unlock that item, nor does the time spent playing prevent you from unlocking OTHER items naturally.
The equivalent would be if you had to complete MGS1 in its entirety for one piece of common place gear amongst hundreds of similarly priced items. Oh, and you get it only if you don't pick up new weapons or items or get health bonuses in your playthrough.