I guess the XS Max would be well outside of AppleCare+ territory, but for those of us who upgrade every 2-3 years, AppleCare+ is great.
It's literally insurance for your phone except you don't have to deal with the insurer.
I've only used the Express Replacement Service part of it twice, but when I've used it, it's been like magic. I get a brand new (refurb probably, but who can tell) phone within 2 days, and then I send back the old one.
No questions asked, no weeks of wrangling with the insurer.