My bitcoin journey begun with this forum and a number of youtube channels about bitcoin. At first I was subscribing to most of them to show my appreciation for their work, but after a while it became obvious that most of them do it for the money, to get various sponsorships, using their audience like a guru is using his followers to work for him. They weren't giving anything to their audience, but trying to make the audience do things for them, like using referral links, buying coins they were recommending, paying for limited content. Also, they had no real content on their channels. It was all news from other social media like coindesk with their own comment on top and a more catchy title. It was always something big and exciting and in reality just another shitcoin with their own promo code.
Avoid these people like plague. You can easily recognize them by their explosive thumbnails. There's always a lot of exclamation marks and stupid headlines like
Is this over?
Is bitcoin done?
Crypto manipulation!
Warning to all holders!
Big pump incoming!
These coins will explode in 2023!
See something like that? Tell Youtube you don't want to see such content.
To play the devil's advocate for a bit:
1 - They must've done something right, as you yourself admit they introduced you to Bitcoin.
2 - Creating good content takes a whole lot of time and effort. To be able to deliver good quality, well-research content on a regular basis, there must be some sort of compensation (aka income). Add revenue on YT vids is not as high as people might think and it's very easy for a video to get demonetized. So almost all content creators have to resort to other means of generating revenue (referrals, sponsorships, selling courses etc). That's not inherently wrong.
3 - The ugly truth about attention-grabbing thumbnails is that they work. We all know it's a cheap trick but we all fall for it. Your eye might not even register the presence of non-flashy, "honest" thumbnail if it's surrounded by attention-grabbing ones, that's a flaw in human psychology.
So to evaluate content creators, I'd be focussing on whether they have integrity, competency and if they deliver truly valuable content rather than just looking at the thumbnails they use or whether or not they use referral links etc.