I'm a good example of this. I'm an ad guy and a marketer, and as such I'm much more intimately familiar with how this stuff works, what it collects, and how it is used than most. I'm also going to expand what I say beyond just the world of apps, because it is really applicable to anything digital these days, whether it is in an app or on the web, because I hate thinking of those things in silos.
To be a successful marketer in this day and age, proper analytics is a non-negotiable requirement. If I was interviewing somewhere and they told me that I had to market and advertise for an app or website, but that I couldn't track things, that would be the end of that discussion. I would be set up for failure from day one. If anyone wants to make a case otherwise, I'd ask that they share their credentials as someone sufficiently experienced and qualified to make such a case, and how they would go about being successful without that data when pretty much any significant digital (or non-digital to an extent) strategy these days requires that data to measure success and optimize for it.
So there's that piece.
As an end-user, this is often a source of cognitive dissonance for me, and it has grown over the years. 8+ years ago, I had very different feelings when people talked to me about what was being tracked and how it was being used. It was less audience-centric, cross-device/channel tracking was not really a thing yet, and we didn't have anywhere near the aggressive tracking that FB and Google have today (even though some of the first signs of that were showing up publicly perhaps).
Today I'm pretty paranoid about the data out there, who has access to it, and how that data can be used, both for anti-competitive business purposes, as well as more nefarious uses, even if unintended (such as via a data breach). I run noscript at home, and Firefox with uBlock Origin at home and on my phone.
I personally don't have an issue with people collecting usage data for improving the product and their business, but there's a weird gray area for me when they start using that data against me for things like dynamic pricing, dark patterns, selling email hashes to cookie onboarding services for retargeting, etc. I also recognize that while I may not have much to hide, I know I'm pretty lucky in that regard compared to others who may not want to be identified by certain means, and I fully respect and appreciate their desires to remain untracked in that way.
For example, I am pretty upset at how Reddit is moving towards increased tracking and verification as they march towards heavier monetization. That's an example of a community with many people who NEED to remain untracked for safety purposes, and that data, were it to fall into the wrong hands, could prove dangerous for them. Likewise, the simple act of forcing the collection of it could turn them away from such a platform which could indirectly cause them harm (suicidal users seeking help, abuse victims, whistle-blowers, etc.).
So where do I net out with all of this and how do I sleep at night? Well, for my part I do what I can to be sensitive to protecting PII, not collecting data that I'm likely to never need, and really weighing heavily the tradeoffs and risks when I implement something like the Google or FB tracking tags anywhere, and what I may pass into them. I also make an effort to set the record straight and educate people on what I know of tracking, and how to best limit collection if you are concerned, because I think it is something everyone should be educated about so they can make those decisions in an informed matter themselves.
I respect that some people hate my profession and think I'm evil, and I'm never going to win those people over, nor do I really feel the need to. But I'll say that to be competitive with marketing a product or service in this day and age, you dramatically hurt your chances of success if you DON'T have some decent tracking, and so the realities of the situation often dictate what happens in many businesses. My guess is the people who have such black and white views haven't ever been tasked with marketing a product in a true professional capacity, and if they have I'd love to hear their stories and what led them to their views.