I think very few franchises manage to actually add on to the world with sequels. Final Fantasy, for example, would practically reinvent itself with every iteration. Not anymore.
But I disagree that this is a recent problem. All Mario games and Pokemon games (or most Nintendo games) have hardly changed from their first appearances. I think that contradicts your statement: "If you are a gamer from 80′s you might remember those days when sequels barely existed and you were always treated with new IPs then and now."
I don't think that was ever the case.







