If you work at a job where you don't feel the agency of your decision making and output, if you're working for "the man", it can be relatively demotivating.

If you're working for yourself, and you know why you're doing something, and how you'll benefit from your labor, you'll have a more direct link to your motivation.

If you're working for an institution and you don't feel that agency, you might need a meta-objective. This is where people look to climb the ladder, or learn a skill that allows them to bounce to another institution for more pay and responsibility, etc. If you can't see any of those paths, it can be very difficult to feel the motivation, unless you're intrinsically motivated and all the work you have in front of you feeds your needs.