From the twitch pages

The desktop web browser experience of twitch.tv and supporting sites, officially support the latest two versions of Google Chrome, the latest two versions of Mozilla Firefox, the most recent version of Microsoft Edge, and the most recent version of Apple Safari.

https://help.twitch.tv/s/article/supported-browsers?language=en_US

What’s your browser version OP, so we can rule out whether it’s just a version issue

Peertube is a video and streming platform (like youtube) and owncast a streaming platform (like twitch) that are FOSS, self-hostable and connected to the Fediverse. Although I don’t think getting any amount of viewers on those platforms will be any easier.