I think it somewhat depends on the market you're going after. If you're doing b2b with a product that is clearly a differentiator, you can probably build an mv

I think it somewhat depends on the market you're going after. If you're doing b2b with a product that is clearly a differentiator, you can probably build an mvp and talk directly to customers and get them to try it out and get feedback. For this you may be able to get by with 'good enough' design. If you're doing a consumer product, where you won't get to speak to most of the customers until after you get them interested or even using the product, then you may need to focus more on design. Keep in mind, the less features you have, in theory the less design you need, so keeping it bare-bones at first is always a good start.