The future of any successful design tool today has been through VC funding. Look a the funding rounds that Canva and Figma have been through to get to where they are. Also this space relies heavily on free organic traffic to sign up to a free plan followed by making huge shifts in user behaviour so that they love your tool. It takes time for users to convert!
We had a PPC agency working with us at the time. We were able to run ads profitably, we probably generated roughly around $30K to $40K on a $10K monthly ad budget. So we decided to keep the deal going until we found VC funding.