Do logos matter as a startup?

No.

The branding and logos of most startups evolve and change as they figure out who their customers are and what image they want to present.

Instead of focusing on a logo, focus on validating your product and acquiring customers. You can allocate design resources into branding and UI once you have customers.

Do not block yourself by not having a logo.
A quick way around logo block is to start with an all text logo of your business name.