A browser with broad accessibility (in terms of low energy and bandwidth use), that is convivial — in the sense of a convivial tool.

The most obvious step is JpegXL compatability — an image format that can significanlty lower energy and bandwidth use related to images, evey beyond the compression formats used today.

Beyond that, there are many interesting possibilities. HTMX and hypermedia support/orientation, to make the browsing experience lighter, more accessible, and less energy and data intensive, with all of the expected UX and interactions of modern hypermedia tools.

A "web app" suite — web apps for email clients, web apps for office tools, web apps for whatever we want, and thinking about what it could look like to think about this at the browser level. This could be a more privacy respecting and lighter approach, to transcend the status quo of app packages and clients we have today.

LibRedirect (e.g. automatically re-directing URLs to alternative websites/frontends when desired — e.g. alternative frontends for Reddit, Twitter, YouTube) with easy user configuration and customization

Doing Tabs better — whether through design (e.g. stacking, vertical, tab groups), and functionality (automatic tab suspension to relieve memory usage, like Orion natively and several web extensions offer)

And exploring how a browser could be extended, in service of convivial computing and a tool for people — for example, with an emphasis on HTMX and hypermedia, perhaps it could be simpler to see how certain components / features work on any website (e.g. pagination, transclusion), with a focus on equipping people to copy and remix those components in their own work.

Likewise, getting into better search engines, etc etc. Lots of possibilities.