HTML has evolved in the last 15 years to be a platform for applications. The early Bootstrap was a terrible Rube Goldberg machine because CSS didn't have civilized layout mechanisms such as grid and flexbox. Newer frameworks like Tailwind are more sensible, but still add 50k to your bundle, and if your app is complex and developed under deadlines you probably have components that use Tailwind and Bootstrap and emotion and styled-components and raw CSS and you still have to write some SCSS to get the styles just right in the end.
I've been investigating the accessibility of various <Modal> components and found that they all suck because they do complicated things with <Portal>(s) and various-aria-attributes. HTML has had a <dialog> component that properly hides the rest of the page since 2022 but barely anyone was using it.
If you stuck to using Tailwind or Bootstrap or raw CSS and used a minimal widget set you can make small applications with any framework. If you wrote raw CSS and made the most of the widgets that come in HTML5 (like the new stylable <select>) you can make tiny applications.