Average and peak numbers for both those games in the last 30 days are still higher than Elite. Less content creators for a buggy niche game will mean less people getting interested in said buggy niche game. Especially new players. It was because of several prominent ED content creators that have produced less content and streamed other alternatives was the reasoning for me choosing go give a certain alternative a try.
Of course they're higher. Elite is a niche game and those games cater to the casual market. It's why NMS is more popular too, despite it falling flat on it's face at launch. It's also no coincidence that a casual game has more people streaming it too. Wider audience = More followers.
Personally I've always been a fan of sim games. Not so much full-on sims like DCS or Flight Simulator, but "simcade" types that still feel like games and not doing taxes. My brother is who got me into ED. I saw him playing it one night and was interested to try it out. I watched ED streamers later for tutorials, but none of them scream "ED hype man" to me. Even Obsidian Ant has frequent criticisms, and he's the closest content creator to a marketing ad for ED exploration. Most people who might be interested in that facet of the game alone are immediately turned off if they research how deep the game gets mechanically. It takes a certain type of person to stick with ED, let alone try it out for the first time.
I've also watched smaller streamers playing ED, and while they are the most likely to talk up the game (from my experience they are most often in the Honeymoon phase), if you listen to them they are also the most likely to not know how certain aspects of the game actually work. Most of them don't last long, because ED has a small player base and it's just not profitable for them to stream a game that has such a small, albeit hardcore, audience.
I just don't think ED is the type of game that hooks people in through streamers. It's more of the type of game that looks complicated and intimidating if you watch someone stream it. ED livestreams are never as popular as casual games. The highest amount of average viewers on Twitch is lucky to break 150, and if you look at/participate in those chats 99% of those people are not new. They're already playing the game.