If you only pursue what you love, it will not benefit you
A lot of times most people will think: "I just want to do what I love".
That's what society have ingrained in our thoughts.
And if you think about it, it's very much self centered.
And self-centeredness doesn't benefit us as much as we like to because we're not producing value.
And we have to understand value = profit and revenue.
So instead of asking "What should I do that's fun for me?", ask instead, "How do I create value and benefit others?"
Bringing back to context.
Don't find a niche purely based on your passion or interest because that's where most people fall in the trap in.
Honestly speaking, if you start to research something, you'll naturally find an inclination or interest and admiration towards it. And this can be anything, really.
Hobby and work has to be thought separately.
You don't start earning serious bucks until you start treating this as a real business and not just a hobby, ie. dedicating a fixed time everyday to work on it, setting goals, etc
Because I'm very sure most of us here wants a better future and has enough of the coporate job you're stuck in and that's why you're here, finding a new beginning in this rapidly evolving world.