This game is so hard to finish

I'm a new player I've been playing many hours of this game for a week now and I enjoyed it but why is this game so long and tedious and so time consuming to finish. I'm wondering how many years and people did it take to make this game Borderlands 2? It manged to beat my playtime in MHW, RDR2, I feel like out of all the single player games out there this is by far the most time consuming and very open world compared to other games.

Also is bundle dlc worth buying? It's discounted now on steam the one that includes other dlcs where parts of the map the one with the * symbols you know? I find this game enjoyable but boy it soaks up a lot of my time lol. I feel so immersed. I haven't reached the ending yet I don't know how long I am in the story but I just recently passed Roland's death. I love being a raider but man his death makes me somehow sad. The amount of world building in this game is too much that I start to wonder how many years did the creators made this game it's so vast and plenty that I believe this game can't be created easily in a short amount of time.