apple giving updates to its 7year old iPhone 5s but Samsung can't provide monthly updates to its new devices till Samsung should give regular updates for 3year monthly
Samsung Galaxy M51 is on quaterly security update list, so you will recieve security updates at an interval of 3 months. Currently, as far as I know, November security patch is rolling out for M51. Kindly go through the link https://security.samsungmobile.com/workScope.smsb
Please don't be so impatient about updates. Samsung is pushing update to M51 region-wise, when it's time for us, we will definitely get it.
