What is the most common Startup mistake?

Shipping with bugs.

no marketing at all

They focus on: Product: 70 Marketing: 20 Sales:10 Customer Success: 0

Being in love with your solution more than the customer problem.

I would say that this is not a serious attitude to marketing. That is, the product is made for the sake of the product, and not for the client.

Maybe all of them? 😂

I think ignoring customer feedback is the common situation that start-ups may encounter in the 0-1 phase. User feedback is the most important thing, but some founders focus too much on the financial part.