I chose the Mac and iOS specifically BECAUSE it is a walled garden. Just as people choose communities they want to live in. If Apple is forced into being a homogeny with Android or Windows then what's the point?
Fortunately nobody is stopping you from continuing to enjoy the walled garden. Simply don't download anything from outside of it. Nothing has changed by allowing alternatives so long as you don't use those alternatives.
It's like if your chosen community introduces a communal grill but you're a staunch believer in only obtaining barbecue from your approved barbecue joint because nobody ever got food poisoning there. You're absolutely free to continue to go to your safe barbecuery while the others in your community enjoy their backyard cookouts.