I guess it’s hard to say, there could be a number of options, depending on the reasons of your coworkers. Maybe your docs aren’t useful to them? E.g. they might

I guess it’s hard to say, there could be a number of options, depending on the reasons of your coworkers. Maybe your docs aren’t useful to them? E.g. they might see the docs as too basic, too advanced, unintuitive, or too hard to maintain. Or perhaps they prefer to be indispensable to e.g. ensure job stability?