For charts and plots -- I was thinking about the same thing today, actually! I've usually done those manually with SVG and JS. I was wanting a framework, and spent 30 minutes or so today looking at tools to use R diagrams on the web [0]. Also thought a little bit about making my own library. There are existing libraries like Plotters that should plug and play with Leptos just fine [1], but I haven't tried any yet.
If there was a way to embed R plots without a lot of pain or CPU cycles server-side that would be fabulous. I would love to see an example of that. Plotters is pretty decent, I've used and abused it in a few projects over the years. But if I wanted something dynamic, I'm not sure how well that might go.
It does look like SVG and JS would be the way to go. Maybe there's a nice trick there, not sure.