It's not in the top 3 for units sold, it's in top 3 for dollars grossed, just a little correction there. The OG being among the most popular games back then means nothing. Look at what you've said. You said it sold 10 million on PS1 right? PS1 has been around for almost
thirty years.
Now, the same game got remade, and just the first part alone sold SEVEN million in 3 years.
How can you sit with a straight face and say that's not a huge feat? It literally sold almost 70% of the original game's sales alone on PS1 in a fraction of the time.
It seems that the issue is you can't come to terms with understanding that games like COD/GTA and others have inflated sales numbers for games so much that now we're even having this ridiculous conversation about 7 million copies sold for a game is somehow 'not good'.
What does this have to do with popular 3rd party IP's? The original was still largely popular on PS1 mainly. You even said yourself it maybe sold 5 million across other platforms. Why are you trying to remove the time frame? That's almost 20 years of sales across other platforms. You're unfairly comparing almost 30 years of sales to one platform while trying to remove the time component of that.
Crash Bandicoot, Tekken and Tony Hawk games were among the top 10 best selling games on PS1, but today they're not and those games are on all platforms mainly. Should those games go back to being exclusive?
You're ignoring big variables to try and create a narrative that just isn't true. Exclusivity/multiplatform doesn't necessarily suggest a game will sell/flop. 3rd party games that have been third party can stay third party. Exclusives that are selling well don't "need" to be multiplatform.