Having been on the solstice 2019 and 12+ meals in Luminae I can say without a doubt the food ingredients + quality isnt near Oceania(execution on how well the fish is cooked etc of course can vary by ship/staff). The french restaurant(for a bit extra $) was excellent and on par with Oceania. Add the crowd size and premium service there is no doubt Oceania is a decent step up... but of course it also cost more.
Both are decent choices. When my kids were younger I preferred Celebrity as its more family friendly and had better entertainment. Now I prefer Oceania.