But the vast majority of players who play as a Paladin in 5E, select a deity.
Citation needed.
Not really, its common sense, but ok.
Numbers may vary depending on setting, but I would assume the vast majority playing in the Forgotten Realms do.
Pre 5E I believe it was required (correct me if Im wrong, going off of memory here). So most ppl pre 5E did. Most of those ppl, would probably keep doing that. Lorewise most Paladins do, so anyone who is paying attention to the lore, the spells, abilities would (imo). Those who dont care too much about all that, will most likely go out of their way to make a background or backstory to justify not doing it.
Personally I have yet to see a paladin player who hasnt, (that being on streams or RL). I know about 30 ppl RL who play dnd. Of the 9 examples (7 ppl) I can draw from (10/8 if including myself) , all their paladins had a deity, and I was not their DM.
And well it makes Logical sense. Now to what extent the majority of players/dms interacts with it after character creation, is offcourse a wider question.
