asked

The game quite literally cannot support an open world. Games are not magic- you do not simply wake up and go "I think I'll convert the game to open world today". There are hundreds of reasons this is never going to happen. The game is not designed to let it happen. There are so, so, so, so many aspects of everything that would need to be completely uprooted for it to happen.

200 sims is also insanity. Most players have such outdated hardware they struggle with the existing limit of 20. 200 is ridiculous and would slow down even the strongest hardware.

A small increase would be a more realistic goal and could still make a difference. Like 25 or 30 at most. 

These limits can be increased with mods and my couple of years old mid-range gaming laptop is running smoothly with more sims on a lot, so I think 20 is setting the bar quite low. I'd like to see it become something adjustable in the game without using a mod.

The sims 3 open world

Yes? What about it? Do you have any further information you'd like to supply?

EA is capable of the impossible EA is the most powerful gaming company in the world and the proof is the quality of its games

The Sims 4's foundation is not capable of being converted into an open world. They would have to scrap the entire game and create a new foundation that is open world. By the looks of things lately the best they have been able to do is distancing the lots to make the worlds "bigger", add in festivals and in turn get complaints from simmers who hate having to make their Sim run or bike across the place to get somewhere.

Nobody said EA is incapable of designing an open world game.

The Sims 4 is not an open world game. You cannot simply "make it open world". That's not how any of this works. You are doing the equivalent of saying taco bell can make chalupas, therefore, they can transform my hamburger into a chalupa.