My Nextcloud instance runs reasonably well on the server side, and my desktop and phone are able to render the web UI reasonably fast when I want to...but I also have a tablet with slow hardware and wifi that is just unusably slow with the Nextcloud web UI. Like, it'll take multiple seconds to render the login page, but only on this one device.

Does anyone know of an alternative web UI for Nextcloud that's optimized for downloading and rendering on slow connections/hardware?

Edit: I'm already using Nextcloud, and I'm using it for quite a few different services, some of which have native apps available, some of which don't, and of course even when an app is available, not all the features are implemented in it. The specific device I'm dealing with here is a Linux tablet, so while I can use native desktop applications for some features, it's not like it can just run Android apps. But the problem would apply to any comparably low-powered hardware like, say, an old laptop that can run native apps and efficiently-designed web applications well enough, but struggles with modern throw-a-million-javascript-libraries-at-it web development.