I share the same thoughts as you. Many names on the list are unknown to the community as they don't even have a marketing campaign here or on other forums or platforms. I have never encountered any of them, even if they've existed for a long time. It is part of being the best to brand themselves and create a platform where they can interact with the gambling community.
Bets.io and Cloudbet are already present, but the others are either not here or not noticeable due to a lack of campaign. If we look at one of the largest communities of gamblers, Stake and Duelbits are very visible and they have earned the respect of the gambling industry.
Or maybe most of us here in the forum are not only familiar to them? That is why we think their reviews are biased. Also because they pick a casino which are less known in the forum. But, this thing as well. I mean a lot of us will easily judge a casino which are less known in the forum, but we don't that they are actually legit and one of the best. If I remember, some casino in the list had a campaign here before.
When I visit other sites and review sites, I can also see them there. Maybe you are not that active here or you are new here for you to not notice them? And then maybe you are not really into gambling for you to not see their ads. I'm not also biased like you, I just say what I saw and think.