What's your opinion on paying for marketing / ads to get initial traction?

I've been developing Scipress.io - a writing platform like Medium.com, where you can sell access to content - for almost a year now, and haven't earned a single dollar of revenue.

I'm not particularly surprised or discouraged.. it's a big platform that needed a lot of development for the MVP. But I've finally reached the point where I'm proud of it, and I think its offering can compete with the big boys (Medium, Substack, Material for MkDocs, et. al).

So now I'm shifting focus towards user acquisition. I'm doing my usual strategy of direct messaging people on social platforms, making a few Reddit posts, etc. Have gotten some good feedback, but it's slow going.

So far, everything's been organic and self-funded. So, it has cost me a lot of time and opportunity cost, but not much cash. Now I'm thinking the platform needs a "shot in the arm" to ramp up marketing, but ads and agencies are expensive. And I think there's a good argument to let the platform grow organically..

What are your thoughts? Have you paid for initial users? Is a product doomed if it can't go from 0 - 100 organically, or could it just be a slow starter?