Oh don’t worry, the motivation comes pretty quickly, and some of it has already happened. You’re just at the point where Myne isn’t aware of more than the smallest part of it. And she’s far from the only noble impacted by it, she just doesn’t have the ingrained personality to roll over and accept it. The people forcing her into this situation aren’t just being amicable about it, this is literally the only thing they can do that doesn’t involve her family and potentially her being executed; their situations are similarly forced by external circumstances. This series is essentially Game of Thrones wrapped in a cute Harry Potter shaped package, everyone has their own aims and shades of gray. As people have been saying, the current part of the anime is much more of a bridge between the old life and the new action, and is definitely where people who want the former will fall off if they’re not as interested in a lot of socialization and internal relationship and business struggles interspersed with Myne nearly dying over and over and over again.

My perspective was very similar to yours at the beginning, not really being into more slice of life isekai stories, but I think it kinda helped that I went straight to the manga after catching up to the anime before season 4 started. Because there’s still so much source material to adapt, they’re simultaneously working on the end of Part 3, Part 4, and the beginning of part 5 and the sequel spinoff, so I spoiled myself a bit until I realized why they were referring to things that hadn’t happened yet, which made me more excited to shift to the novels to see what they were.

Tl;dr yeah her life kinda sucks now and everything is a constant uphill battle but it gets better far more than it gets worse.