streamlink-twitch-gui 1.10.0 requires streamlink 1.4.0 at least.

From the release page:

This will be the last release with support for Python 2, as it has finally reached its EOL at the beginning of this year.

Streamlink 1.4.0 comes with lots of plugin fixes/improvements, as well as some new features and plugins, and also a few plugin removals.

Notable changes:

New: low latency streaming on Twitch via --twitch-low-latency (#2513)
New: output HLS segment data immediately via --hls-segment-stream-data (#2513)
New: always show download progress via --force-progress (#2438)
New: URL template support for --hls-segment-key-uri (#2821)
Removed: Twitch auth logic, --twitch-oauth-token, --twitch-oauth-authenticate, --twitch-cookie (#2846)
Fixed: Youtube plugin (#2858)
Fixed: Crunchyroll plugin (#2788)
Fixed: Pixiv plugin (#2840)
Fixed: TVplayer plugin (#2802)
Fixed: Zattoo plugin (#2887)
Changed: set Firefox User-Agent HTTP header by default (#2795)
Changed: upgraded bundled FFmpeg to 4.2.2 in Windows installer (#2916)

https://github.com/streamlink/streamlink/releases/download/1.4.1/streamlink-1.4.1.tar.gz