Apple built their controlled ecosystem and set their rules. And now others are insisting that Apple should not have that control (even when they themselves are doing the same thing).
With an iPhone, for better or for worse, I can point them at the App Store... app... ("say 'app' again! I dare you!") and be reasonably confident they're getting the official Instagram app. There are multiple apps with "Instagram" in the name, but the official one is the top search result.
Contrast with the Chrome Web Store. The search results for "Instagram"[0] have a bunch of results from who-knows-where, and many of them contain the official logo somewhere inside their preview image. They all look they could be the real thing, but as far as I can tell, none of them are.
Going to the family's house for holidays use to mean spending some time cleaning the weird programs off of the in-laws' computer. Now it means uninstalling the odd Chrome extensions they've manage to find, and making them change their website passwords.
If it ever becomes super easy for Apple users to install random software they find on the Internet, I am throwing my older family members' iPhones into a lake and giving them a flip phone.
[0] https://chrome.google.com/webstore/search/instagram?hl=en-US...