But too many things to do IS a problem for raiders. I understand you're a casual player so it's different but like... just no. There are definitely better ways to implement features like this without also including the hardcore playerbase. I think the point OP though is to show the difference between the philosophy of WoW back then vs now.
The grinds were mostly optional with a very few rep rewards being a mandatory thing you needed to do. To this day, I've never even finished the Argent Tournament dailies. That's still content I could technically go back and do to do this day for something. The difference with that and Legion/BfA is that these World Quests you do to progress your character are all 100% meaningless as soon the expansion goes away while content like the Molten Front or the Argent Tournament remains content you can do forever.
I think they just handle player power increases incorrectly. I'm all for you being able to do your own content to boost your player power, but why does your content and your power also need to affect my power as a raider? And subsequently why should MY content be useful for your content? What if solo content made you better at completing solo content?