Re launching my project. Is SEO a good marketing strategy?

A few months ago I gave up on my first online business.

I had created a website for solopreneurs, I planned to grow its visits, monetize it with adsense and a newsletter.

It was very difficult to get visits and subscribers to the newsletter, the main channel to do so was my Twitter account and it was not giving results, so I decided to give up on the project.

This week I was checking the site, since I am still paying for the domain, and I noticed that organic visits have increased.

The site today has approximately 4 visits per day. I know it's very little, but that was achieved without any work.

Do you think it is possible to increase visits with SEO and gain subscribers to my newsletter?

I've been working on it, I rearranged the page, and I plan to make a newsletter exclusively for solopreneurs.
It is a good idea? How can I validate it?
I appreciate your opinions. The site is fintiux.com if you want to see my work.