**Feature summary**:
- ECharts has many chart types, of which the Charts extension only (currently) supports a few. Some notable ones from the previous Graph extension that are missing include (sub-tasks would be desirable):
-- [ ] Stacked bar charts (T373347)
--- Both uses less space than a side-by-side bar chart and better shows totals per category
-- [ ] Scatter plots (maybe possible currently but I can't find any info?)
--- This is probably the simplest to implement considering there is already a line series. Useful for graphs depicting relationships between variables.
-- [ ] Maps (choropleth, not those creatable in Kartographer)
--- Kartographer is helpful for creating detailed, interactive maps; for smaller scale choropleth maps that involve repeatable coloured in elements, the previous Graphs extension was used heavily
-- [ ] Tree diagrams
--- There are non-Graphs versions of such charts on the English Wikipedia, and I am not sure of the extent to which this type was actually used (though it was supported)
-- [ ] Timelines (T137291)
- All of the above are natively supported by ECharts.
- Charts should not seek to just be emulate what Graphs did, and so it might be worth considering some other charts, subject to use, such as sankey diagrams and treemaps.
**Use case(s)**:
- Users are currently unable to use any of the above chart types. The first three are used very often on different Wikipedias and are currently inaccessible.
**Benefits**:
- At the very least, Charts should supply most of the series that Graphs previously provided. I, as a user, want to be able to use a reasonable (but not excessive) number of different data visualisations.