The raw HTML/SVG or base libraries approach may well win out, but it does make it quite hard or impossible for humans to follow along and verify for instance where the numbers on a chart came from.
I think in a future where AI's doing all that verifying (or we just trust it), the AI might still prefer to use a DSL like ours because the abstraction maintains consistency, lowers maintenance, and saves a lot of tokens.
But the most helpful bits of a structured DSL are for sure still for humans. The structured format ensures things are readable and testable. Ours also enables a generative UI, which for now at least is still a much faster way to make visual edits while working with an AI, vs always through it.