Unfortunately I fear you could be right. Using the grind as a way to upsell “boosters” or whatever is sadly a time-honoured tradition in games development.
I worry Asobo has forgotten what the career is for. Fundamentally MSFS is just flying, that is the game. However, you have so much choice on where and what to fly it can be overwhelming. I’ve always used careers in flight sims to effectively give me suggestions on where to fly to next, letting me explore places I otherwise wouldn’t have. You also get to do some fun role play along the way, develop some skills you maybe wouldn’t have developed naturally, and create a sense of progression. The point of a career is not to force people to fly monotonous missions over and over just for the sake of it: in my view that is very much putting the cart before the horse.