It's mealy, tastes pasty and bland with no flavor. Honeycrisp so much better tasting and texture! Red delicious were bred to have a dark red outside and look like a classic "apple" while sacrificing the apple flavor inside.
https://en.wikipedia.org/wiki/Red_Delicious
No idea if this is still true of what is currently sold under the name. All apple verities are clones so the they should be (mostly) the same but the verity is old enough to not have anyone protecting the name.
Specific varietals are from cloning specific branches widely, but at some point it often gets ‘lost’ due to natural imperfect cloning.