This decision because you are releasing too many new devicea with the same dev team they can't cope with this large number of devices
As for my case Mi max 2 miui 10 stable came after a decade full of bugs while beta is more ripe and more stable and we never got any android 8 because devs are busy
Think twice
You are tking the way down so fast
Many alternatives are out there now but miui was the difference but without beta all will be the same