The gamble is that you can cruise on the senior engineer’s diminishing understanding for a few years until models become good enough that you don’t need any humans in the loop and you can fire all those expensive seniors.
The tragedy is having a bunch of those senior engineers writing blog posts and what not of how productive they are, without realising that it means business now needs less of them.
I suppose that if you don’t believe that models will be good enough to work completely without senior engineer help, positioning yourself as a master prompter is a good move to improve your chances of not getting fired.
If all you have are being good at prompting you are gone. Business is going to prefer new grads who have taken some class in ai prompting (which many schools now offer). Doesn't matter if the class in ai prompting isn't any good. What matters is the idea that they had a formal training in this thing, and that they are willing to work for far less pay than any senior.