You say local consumer law provides 6 years of coverage - but that only covers manufacturer faults. In all my years of iPhone ownership (8+ years), I've never bought a brand new iPhone that had any manufacturer faults.
AppleCare+ is only really useful for accidental damage repairs. The new, larger OLED panels are VERY expensive if you're not covered by AppleCare. Apple currently quoting £326.44 for an out of warranty 11 Pro Max screen replacement.
AppleCare+ for the 11 Pro Max costs £199 and includes two incidents of accidental screen damage replacement (with a £25 excess fee). So if you accidentally drop/damage/crack/whatever the screen just once and you're covered, you more than get your value, even if you include the excess.
Phone insurance that includes accident cover has a larger excess (usually £75-£100) with any claim, and they usually make you settle your entire insurance cover at the time too, so works out to be a similar cost to AppleCare+ in most cases, but AppleCare+ is likely to be much less hassle if you do need to use it. AppleCare+ doesn't cover you for loss or theft though so phone insurance might be the better option if you've had bad experiences like that previously.
Personally, I think it all comes down to how accident prone you are - if you damage/crack the screen once or more times a year, then I'd say it's worth it if you're buying a brand new £700-£1000+ phone. If you're generally very safe and always have a screen protector and case, then I'd say give it a miss.
