My primary device is the iPhone 15 Pro. While I've gone back and forth between Android and iOS over the years, I have been firmly planted on iOS with my iPhone as my primary device for the last 8 years or so. While it's definitely due to my reliance upon the whole Apple ecosystem like Apple Watch, AirPods Pro and Apple Card, I'm also doing iOS development and generally just enjoy the higher quality design and apps available on iOS.
Google Fi is my wireless carrier of choice, having switched after more than decade on AT&T. I have now been using Google Fi for many years and now use it with my phone and iPad Pro. Yes, it works on iPhones and has 5G!
I love Google Fi for a few reasons. First, it's just a super easy to use mobile carrier and since it uses your Google account you get great security off the bat since your Google account can be locked down with two-factor auth, security keys and Google's Advanced Protection Program. Second, it works virtually everywhere internationally with no change in price. That being said I also use Airalo to buy cheap eSIMs for more data when traveling.
That's the general gist but there's more to it, like automatic network switching and automatic VPN if you're on Android. Here's my referral code if you want to give it a try and get $20 of credit. I have sucessfully used Fi on recent trips: New Zealand, Greece, Cayman Islands, Rwanda, Tanzania, the Netherlands and the UK.