We could do this at least as far back as 96, I can confirm. Even without Bootstrap you can just write a super simple HTML page, with bare minimum markup and layout, and just focus on getting the functionality right. No CSS or Bootstrap needed. There's always time to iterate on the prettiness. Plus if a customer/user likes your site when it's "ugly" but functional, and especially will pay for it like that, then they might like it even more when it's "pretty".