How is the Raspberry Pi still relevant? There are better/faster/cheaper/more open SBCs.
Somehow they have managed to convince people they are open source (they aren't) that they are a good architecture (they aren't) and they are good to teach children about hardware on (they aren't).
I'm being flippant, but I think the point is important. What Raspberry Pi really brought to the table was making hardware hacking feel accessible. The sorts of people they're appealing to aren't looking for the fastest or best system, they're looking for something that feels easy and straightforward. They're cheap enough that I doubt price is a major consideration, and openness is almost a non-consideration among the populace at large.