> 1 good ongoing client is better than 100 one-off projects with different clients.

I mostly agree with you, except much of the freelancing allure stems from working on new and exciting things, avoiding burnout and boredom. So I'd modify that statement to:

3-4 good ongoing clients is better than 100 one-off projects with different clients.

Edit: didn't read the last half of your comment. If running a startup or building a product is your primary goal, then I absolutely agree with you.