I used to write tech How To articles on my site around 15 years back, just to help other people. Then adsense came along and I made some money but the primary motivation was to learn and share my knowledge with others.
Now whenever I interview people in my professional life (I'm a CTO and have to interview people for top level positions), they routinely tell me, they had their best interview. For long, I couldn't trace it back to the podcast. After many people compliment me, I asked one what made it a better interview. He said, you let me explain my project and you listened. That is when it clicked. Those are the skills I learned as a podcast host.
I paused the podcast last year, because I got covid and for other personal reasons. With this feedback, I'm going to restart the podcast.
Not all creative projects have to make money directly. There could be 2nd order benefits, which we may not see immediately.
It was still doing hundreds of downloads per month a year after the last episode (podfaded unfortunately, my co-host didn't have any more free time after having a kid). The folks clicking the ad seemed to enjoy the show and from there word of mouth took over.
Like you say not everything needs to make money, but that worked for me(tm) in terms of growing the audience. YMMV ofc, could have just been lucky.
The biggest thing I got out of it (aside from dopamine in the moment of course) was the speaking skills. Just being able to project my voice better, better formulate my thoughts, etc. Well worth doing in hindsight.
E: Aye, this one. Timestamped but I'd recommend the entire video if you're interested in YT nerd stuff https://youtu.be/6pMhBaG81MI?t=472