Why is Update to Androud 5.0.2 not possible anymore?

[Ocean Skipper]

Why is Update to Androud 5.0.2 not possible anymore?
Ok, its on my oldest tablet ... but it works good and I still use it in case the other one fails.
But should this be a reason to through it away?

[Korina]

@ocean-skipper Hello, we no longer support Android 5 and 6, you will not be able to update it.