Data viz used to be my playground, I feel like I can comment on this with some confidence. It feels like the selling point / value prop here is that it supports multiple FE frameworks, but that's where its strengths end for me. It almost looks like a coding exercise more than a library that people would use - seems a great amount of effort went into boilerplate, configs, packaging, documentation etc, but not as much into the features themselves.
The tell-tale brushes in some of the interactive graphs hint at d3 as the foundation layer, and poking through the configs confirms that. The real power of d3 lies in how it integrates data with the rendered elements - transitions, filters, being able to use one set of graphs to drive the parameters of another set, etc. With d3, you get interactivity for very very cheap, it's a missed opportunity here not to extend that (most graphs in the gallery seem static).
Overall there is nothing that makes this stand out over other offerings. Other commenters provided some good examples. I'd mention Altair/Vega as an example of powerful / configurable library that can be driven from either FE or BE. D3 as the gold standard of a low-level visualization primitives library with unsurpassed flexibility. If you're after something more out of the box with a DS angle, Dash does a decent job (and plotly.js for an overwhelming viz feature set). For commercial solutions, HighCharts, as much of a drag as it can be, is still the reliable beige khaki offering. CanvasJS would be another one in that space. If you want to dabble in 3D visualization, three.js is by far both the best starting place and the most robust library you can ask for. Honorable mention for dc.js, as they make good use of the crossfilter approach (driving context/selection across multiple graphs)
The js data viz space is quite full, with some heavy-duty, established players. To be a new entrant on this playing field, you'd have to bring something breakthrough to the table. Sorry.