I’ll add another piece of feedback.

It’s easier to narrow the domain of your market as specific as possible so as to maximize transactions and matching early on.

For instance, Uber launched in one city. This is so that all the growth efforts on both sides go to helping the markets meet. Twitch had to win with gamers before it could win in other categories. Pick a narrow domain for your business, perfect that user experience, then, as other have stated, prop up one side of the market yourself (probably the one least likely to churn forever) until the market can support itself organically.