the only downside for me is that there aren't many mature UI libs for it yet. I was evaluating it for a Tauri-based project but I went with React instead because of this.
You guys can try https://bulma.io/ as a middle-ground. It provides some fundamentals styles that aren't married to JavaScript, so there are never any conflicts with any SPA version. It's not widely used, but it worked well for us before going to Material UI as the team grew and the designers wanted something everyone is familiar with.
Yep, the amount of UI component libraries for React is truly staggering.
I myself am more of a clean, standard HTML with PicoCSS kind of dev, but that model doesn't work for everyone. Some might be surprised how much plain old HTML and the ease of development for Svelte components narrows that gap, but I'll be the first to admit the gap absolutely exists.
Oh! I forgot one of the best parts! CSS is automatically scoped to your component. No manual shenanigans. No weird naming rules your dev team have to agree on. No giving up and just using inline styles. No hacks.
Just make a descriptive class name and write your CSS styles. That's it. You're done.