[D] Creating my own AI model from scratch, is it worth it?

Hey everyone, I’m a web developer teaching myself AI and I was building a SaaS to act as a direct competitor with Jasper AI. However I got stuck deciding between building my own AI model from scratch (for full control and originality) or using existing models like GPT or open-source ones (to move faster and get better results early).

I know there are tradeoffs. I want to innovate, but I don’t want to get lost reinventing the wheel either. And there are a lot of stuff I still need to learn to truly bring this Saas to life. So I wanted some opnions from people with more experience here, I truly appreciate any help.