If Dropbox is a substantially better product (real or perceived), yes, the users complain bitterly (been there, done that).
If Microsoft is simply using bundling as an advantage of market share and undercutting the price of a competitor to drive them out of the market, then the consumer is harmed by the reduction of competition. Once the competitor is gone, what do you think is going to happen to the price and/or competition of that bundle? This isn't new.
If DropBox were substantially better, why wouldn’t enough people pay for it to make it a successful product? If they didn’t, the market has said it wasn’t better.
This is just hypothetical. I’m not making a judgment about DropBox.
But, in the case of DropBox, Steve Jobs said a decade ago that it was feature not a product. That is coming to pass.
I don't disagree that DropBox is a bad example. It is a feature not a product. Maybe better is PowerBI vs Tableau.
But to your point, what should be wildly obvious is that "the market" optimizes for far more than what product is "better", and that "better" (for whatever value of) is often low on the priority, whether it should be or not. It's very often the case that someone in power makes a decision along the lines of "why are we paying for Tableau when we can get this PowerBI thing which Microsoft tells me does the same thing for free". And suddenly, you're trying to learn PowerBI. You can find any number of examples where 'better' things were not what the market picked to survive.
Then you have Slack. People hate Teams so much that there are MS shops that get Teams for free and still pay for it.
Heck, Amazon has it own messaging platform - Chime. I can only assume that after much complaining, even internally we are migrating to Slack. There are plenty of public announcements about “partnerships”.
If Microsoft is simply using bundling as an advantage of market share and undercutting the price of a competitor to drive them out of the market, then the consumer is harmed by the reduction of competition. Once the competitor is gone, what do you think is going to happen to the price and/or competition of that bundle? This isn't new.
edit: autocomplete mishap