Two examples:
YouTuber
Some people were probably making a full-time income from YouTube 10 years ago, but the role "YouTuber" is much more mainstream and well-known today. Plus, thousands (millions?) of people are now full-time YouTubers covering every interest under the sun.
Social Media roles
I saw the following job title recently: Head of Brand Engagement and Social Media - which made me wonder if titles liked this existed 10 years ago? Or are they only now mainstream and more common?
Note: Although I have listed technology-related roles, are there new roles from the past 10 years not principally about technology?
I would guess not millions. All the relevant numbers are confidential, but estimates seem to suggest that having a million subscribers[0] is probably the level at which you could comfortably make it a full-time job, and there are maybe roughly 20,000 YouTubers with that many subscribers[1].
Bear in mind, YouTube is a global platform, so that number has to be spread across multiple countries. Therefore, other than maybe the US, I'd expect that no country has more than 1000 people whose job is full-time YouTuber. Also, for comparison, Lego has about 20,000 employees worldwide.[2]
[0] https://contentcareer.com/blog/average-salary-of-a-youtuber-...
[1] https://medium.datadriveninvestor.com/how-many-youtube-chann...
[2] https://www.statista.com/statistics/292314/number-of-employe...
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