The biggest mindshift required here is you need to really think what can technology solve. Most products being developed by bootstrappers are competing in a space where the problem is already solved. For example the nth job board. Yes in that case if yours look shitty people won't use it. But that is not a problem at all if you are solving a real problem.
I will give you one example, and this is me sharing one of my products for the first time: a custom mobile app for housekeepers in rich families in the UK. The mvp for this was built over a weekend using just basic ios tools. Important thing to understand in this market (custom apps for companies) is that you have to go after companies for whom the branding difference is whether they are number 1..3 or 4.. and 4.. companies die due to competition. So if you can in anyway help them stand out for a large annual contract, they will lap it up.
There are many opportunites like this. Instead if you are building the next app that you are seeing online, ya you are too late.
The other thing is alpha products that are rough around the edges still exist. Forget the Twitter screenshots. When you used Twitter for the first time, did it look like that screenshot? No it didn't. Because by the time it became popular enough, it had been polished a bit.
So what you are doing is comparing a product which is popular now vs a screenshot of the thing before it was popular. If you actually look at the first alpha version of things of popular apps now before they were popular, you will see that they are still rough around the edges. Maybe a little bit less so as a lot of ui frameworks are available now.
Also older stuff look rough around the edges even more because ui trends themselves have changed.
So don't fall for this myth.
Solve something hard using technology with a ready to go ui kit and get the v1 out there as soon as possible.