I can show you my J5 2017 and A5 2017.
The J5 has Android 9 and the A5 only 8. I hope that you see it now.
And yes, I rlly dont understand why A5 2017 is not getting Android 9. All unfairness to me pls D
Even the J series got the update man. They have about 1.5gb ram and only 16gb rom. If they can get it why not we, and we paid more than them. Samsung has cheated us be releasing a phone with outdated os. If in Jan 2020 someone releases a phone with pie, and then upgrade to Q by april,it won't be fair right??