I suspect that Adriene could potentially make a lot more money from her brand than she currently is. I doubt she is rolling in it.
Yes, she will have monetised her YouTube channel, but otherwise her main income streams are her teaching, her roadshow, her small merchandise shop and her service for subscribers / members.
She is careful not to include visible logos in her clothing or equipment. She did a press trip with Adidas a while ago but she doesn't do any major endorsements. There are no affiliate links on her website. She doesn't use her insta or twitter to promote brands other than her own. She also has a career as an actress and does quite a lot of voice work.
This is probably very deliberate - she has undoubtedly decided that longer term it is better for her brand to be perceived as 'authentic' and major endorsements would undermine this.
So Adriene is almost certainly not languishing in poverty. Nevertheless, she makes a huge amount of content available for free at the point of access. I bristled a bit upthread when someone asked if she published a free video every day of the year because I think few people have much idea of what goes into creating the content, and I really, really dislike the general culture of undervaluing content that currently exists.
If someone feels that they have got a lot out of this content and wants to make some payment for it then I don't think that they should be dissuaded.