It's not easy, but it's doable. You have to cultivate the business you want to run (going solo vs with a team). I never personally outsourced much work other than bookkeeping/financials, and instead opted to do things myself. Some things can be slow as a solo founder, but you will find that you can move a lot quicker i.r.t. to product development and support in a way that can give you a real competitive advantage.

For me, talking to users happens daily, throughout the day via email. I try to be as responsive as possible, without breaking any flow state. I do product development when I feel like it (which typically looks like a sin wave otherwise I tend to burn out), or when it's required i.e. bug fixes. The rest is marketing and just sitting there thinking about next steps (some may call it vision).