Actually I’m not a fan of pop ups at all. I think they are typically a terrible experience. I’m not advocating for anything and everything that results in a higher conversion rate…there are certainly instances where that kind of thinking will result in a poor user experience. I’m also not saying that every button should be a solid fill…but your stance that if a user is interested, they will find the button, wherever it is…I think that’s a bit irresponsible. I’d venture to say today it’s not so much that “content is king” it’s “the user is king.” You should want to reduce cognitive load where possible and make it as easy as possible…not say, well most people will figure it out. I think that kind of cavalier attitude is what leads some designers to adapt bad habits…it’s in part about empathy for users, and it’s likely that you have a range of different types of users with varying levels of comfort and familiarity with modern websites and apps. I just think there should be some intentionality…if you’re using ghost buttons in your designs simply because it feels more modern, and you haven’t done any testing…then I don’t think you are making informed decisions around what’s best for your users or your clients.