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As a general shareholder I care. But in that area I think Apple will figure out a solution that keeps the status quo. They're #1 for a reason.
You're right that there are other bills in the pipeline. I think the user experience will be worse off because of them and we'll lose lots of ground on privacy and convenience, but it's inevitable because small, vocal minorities usually win even when they make everything worse for everyone else.
It'll be interesting to see the fallout though. It won't take long for others to connect the dots and start filing lawsuits for any store or platform with any sort of standards. Obvious first targets are companies like Sony, Nintendo, and Microsoft for consoles. But other non-obvious targets will start being platforms. Take Chrome - why can I only use (and maybe I can't and I don't know) Google's Chrome Store to install third-party software? Or rather, why can't I install another "App Store" on Chrome and replace Google's? Maybe you can (and I'd argue it has to be identical in terms of convenience and ease of use to qualify) but there will definitely be other, similar targets for lawsuits.
Two points
1. User experience is already bed. No access to game streaming services and many valid open source apps not available on iOS
2. User experience is not be the only matrix that matters. What about poor indie developer whose app is banned due to opaque App store rules. What about having control over device you bought with your own money
