How important is the landing page in your decision-making process?

What I realized is that I bounce off websites within about four seconds, and that's not enough time for me to actually learn anything about a product. Last month, I decided to spend some time trying out five tools whose websites looked horrible. Three of them were actually great. One is now paid by me.

What was common about those websites: the founder had obviously dedicated all their time to the product itself and not at all to the page. This could be a valid approach, and I had been penalizing them for it.

Of course, I'm not saying design doesn't matter since it definitely matters for conversions.

But what I'm wondering is if anyone here has an opposite approach to the first impression and tries to read changelogs, check GitHub, or ask on the community forum. Or do you bounce off too?