While older & cheaper phones are going to get UI 2 Android 10 but not A8+(2018), isn't this unfair? A8+(2018) was sold with Nougat when Oreo was already released. So a new A8+(2018) was bought with old version for no fault of customers and now Samsung is denying UI 2 Android 10 update for A8+(2018)
According to earlier history, Samsung generally provides on their smartphone maximum two major Android OS updates, regular monthly security patches for three years, and quarterly security patches on its 4th year.
And your mentioned device already got two major updates.