Navigating the Thorny Issue of Receiving Job Offers While in a PhD Program
As an advisor, I want students to be up front about what their long term goals are. If a student is not interested in an academic career, I'll take that into account when I decide to work with them. Part of that calculus is the concern that the student might jump ship part way through.

It sounds like you've been up front and honest about your intentions with your advisor at every step of the way. Your advisor will probably be disappointed, but they will not likely be surprised. I don't think you owe it to them to stay and that seems like a bad reason to stay doing something other than what you want to do with your life. Your own time is simply too valuable and your advisor should respect that.