It depends on whose analysis you read. If you look at some of the interpretations of the early data from Israel, it may be a sign that vaccine efficacy is waning and that people will need boosters soon.
If you look at some of the other interpretations of Israel's vaccine data, you see some problems in their take-up rates. In particular that the over 70s in the UK are 95%+ double vaxxed. In Israel that number is "only" about 85% - which might not sound like a big deal, but actually means they've got at least three times as many people (per 100k population) in the highest hospitalisation/mortality risk groups.
The UK has decided it can cope with more cases, as long as hospitalisations don't rise too high.
Israel hadn't got quite as big an advantage from the vaccines as they'd hoped. Combine that with the vaccines not stopping infection with Delta as well as it stopped Alpha - just a lot more strain than they were expecting.
Incidentally, the UK remains on a tightrope and it's anyone's guess where we'll be once schools/colleges reopen and autumn/winter really kick in. Getting back to normal anywhere is going to be a bumpy ride.