the head of clalit pointed out that the Indian variant might be proving Israel right that the better option is rather getting people fully vaccinated than giving one shot to more people as the UK did because it seems like one dose isn't very effective for the Indian variant
There is no “right” here. One dose might be more effective against non-Delta (Delta is what the WHO calls the Indian variant now) COVID, while two doses might be what’s needed to protect better (but still not 100%) against Delta variant. The one-dose-sooner-to-more-people approach has been around before the Delta variant was widespread beyond India, so this point is moot.
Also, Israel had vaccine supply and administration capacity to vaccinate their entire adult population with an mRNA vaccine within several months, even today many countries don’t have assured access to that.