I think this is ultimately a personal choice. People argue that whether do you want to own 10% of $1B or 100% of $100M.

> "My personal ambition is to build a product that people love and which gives me a decent revenue to hire a few people and to continue working on it."

From your last sentence, it seems to me that you already have made a decision in your head. You are leaning towards building a sustainable bootstrapped business.

I guess focus on building the product, providing value, start selling your product early on and let the market define whether its a billion-dollar company or not.

Highly recommend checking out the following websites: [1] www.indiehackers.com [2] https://getmakerlog.com/stories [3] https://district.so/bootstrappers