I'm sure you're not the only one that feels that way, but I disagree with what you said for a couple reasons:
!) like someone said: all games are repetitive....it's just about whether you have fun or not doing the same shyt over and over...also, in most cases you don't have to do a lot of the side shyt to finish the story, it's optional...
2) I prefer the world being open from the beginning, no locked areas...reason being: it's an open world/sandbox game, and having an area locked cause you haven't progressed enough in the story to go there is bullshyt...I enjoy exploring all the areas of the game as soon as I start playing so I know my way around...open the world up, just make it where I have to progress to do actual missions in different parts though....
3) just cause it's open world/sandbox doesn't mean you can do any and everything you want, when you want...I think that's the problem with gamers when it comes to those kind of games...they wanna be able to go in every building, talk to every npc, etc., cause they feel it adds shyt to do in the game...and that's bullshyt..it doesn't add real shyt to do, that is a lot of time wasting shyt that I'm glad they don't force on us....if i can go in a building, it better be something in there for me to do, if not, i don't wanna go in....also, gamers have to remember these games can only be so free lancing...the games do have a story to tell and the devs want you to play through to the end...
....now i do agree, a lot of the games could improve by adding more main missions, adding more variety to the side missions, and/or making the side missions impact the main story...other than that though: I've been enjoying the shyt outta these games...always have, always will...