Absolutely, do not start the podcast if you wouldn't do it for free, making no amount of money in perpetuity or as long as you want to experiment with. You are most likely going to start a podcast and it will not take off and be wildly successful.
Creating content accelerates your career - but only if you love it
Craft → Career Growth
Don't wait to create amazing things. Often just the act of putting yourself out there can just spur amazing things in itself.
You are the best you out there. So for example... let's say you are a 21-year-old PM, fresh out of school, first year... you just talk about your journey, talk about what you're doing, talk about what you're learning.
Share your knowledge one way or the other. And as you're doing it, you're going to learn a lot more. If you're thinking of a newsletter or something similar, start teaching and sharing what you know and what you're observing. This could be a newsletter, this could be a YouTube video, this could be going to meetup.
There's no shortcuts to knowing a lot... You look at Tomasz Tunguz, who was with Redpoint and now started his own VC firm. And I was talking to him about his blog and he was like, 'I'd just wake up 5:00 or 6:00 AM every morning and write three to four blogs a week for 10 years.'