Shipping beautiful products leads to success. Invest your time and/or money accordingly.
What does beautiful mean?
An example of beautiful software is Notion; easy, simple, and useful. However, it isn't the only standard for being "beautiful." Beautiful can be something more eye-catching, like the landing page for straw.page. It can be minimalist, like this personal website (maybe this will be closer to a portfolio in the future). Ultimately, the meaning of beautiful is in the eye of the beholder.
There are some guidelines to keep in mind.
Look at your target demographics. Younger people appreciate fun, bright themes that are eye-catching and exciting. I would appreciate a fun website much more than the corporate themes many companies are employing on their websites. Older users may appreciate something more easy on the eyes, something minimalist or simple. However, something innovative is at least somewhat appreciated by everyone, no matter the demographic.
Examples
The following are examples of websites that I personally enjoy and give me a sense of wanting to use their product or become more interested in the person.