I'm excited to announce that egui (https://github.com/emilk/egui) is now the first pure-Rust GUI toolkit to implement platform accessibility APIs (most mature on Windows, with macOS catching up), via AccessKit (https://github.com/AccessKit/accesskit). This was just merged in egui's master branch. New versions of egui crates should be published to crates.io soon. Thanks to the Google Fonts team for funding both the development of AccessKit and the integration in egui.
And before anyone asks, a Linux/Unix backend for AccessKit, with a pure-Rust implementation of AT-SPI, is under development, but not ready yet.