How did you know i was going to say something like this?
Their maybe work arounds to get the game working.they may or may not work.All a matter of luck.Again may not work.Someone may of made a program out their to help you run old games,which then may take a lot of testing to get it to feel just right or like dos games[which is what i have been basing this on.],end up with a game way to fast to be playable or a game that is way to slow for your liking.
Interesting thing about games is they work or they don't.Cars degrade over time,the words on the pages of books start to fade away.While a game works or it don't.So yeah,things one day break down or stop working for one reason or other.
With needing to be online all the time,a few more things can make your game stop working,for how ever long.Internet connection stops working for some reason or starts acting up.Servers have to go down for some reason, but will be back up soon.Fun little things like lag,which can take away from the fun.To be fair,this can happen to offline single player games,but it is far far more rare or is done by something that is with in the users control.Titan quest with immortal throne, does happen to get laggy when walking past a few areas in the game.Or other offline games can get laggy as well,when trying to run it on higher settings than your computer can handle or something like using a mod to add more monsters every where in the game.With so many monsters on your screen,your computer can't handle it.
If we are talking about online all the time vs install limits.Then yeah i think you may of got me there,in how long you can play the game for.More so if the install limits don't come with any tool to revoke them,in order to get a install limit back.Then yeah in that case,online all the time,may and is more likely to let you play the game for more time in total than the 3 install limit game.