Professionally I do a lot of product management activity, and as part of my work I need to keep track of the things I need to do daily, weekly, monthly, quarterly, so on and so forth (task management).
Personally I am interested in a lot of areas, so I accumulate a lot of knowledge spread across these junctures (knowledge management).
But then again, my product management also involves validating hypotheses, product ideation and obtaining insights (knowledge development). This would draw from knowledge accumulated from the previous activity, since insights are often of multi-disciplinary nature.
Task management isn’t arguably universal (arguably though), but I think knowledge management and knowledge development would most likely go hand-in-hand together. Most professions, empirically speaking, collect knowledge in order to create new knowledge. I can think of an exception that is lawyers collecting various legal knowledge to present their cases, but I’d still argue there’s a creative element in that process as well.
I think the claim “I don’t think everyone is interested in using the same tool for all three areas” would resonate more with me, since I use Trello for task management, and Obsidian for the other two.