Ruin Explorer
Legend
I don't think that's an opinion that can be backed up by the facts. Some of the cards were there since 3E came out. Others still weren't when 4E was on the way out in 2012.IMHO the cards were all there on the table in plenty of time for 4E to pick them up. It did not.
I will say that aside from accessibility though, 5E did something right that neither 3E nor 4E did, in terms of success, which is simply to resemble older D&D, pre-3E D&D, to seem recognisable such that if you hadn't played D&D since, say, 1997, if you picked up 5E, it would seem like something that made immediate sense in ways 3E & 4E simply would not.
I think this really helped with the 30s and 40s crowd who were ex-D&D players from the '80s and '90s and who either got back into 5E, or in other cases, got 5E for their kids and helped them to get into it.