You could start a Youtube channel and do video interviews, but that's a lot more work.

You could start a local meetup or conference and do live interviews, but that's also a lot more work.

I suspect that it would be best to start out with podcasting, and then branch out.

But as you pointed out, the podcasting interview space is really really saturated. You have to be insanely charismatic AND knowledgable AND creative/unique AND industrious AND lucky to even make a dent.

My recommendation is to find some extreme niche and give podcasting a try. As a rule of thumb, o more than 10,000 people in the world should find your podcast premise interesting.