Using Gnome Web (aka Epiphany), your can create ‘applications’ from webpages.
Using Plex as an example, this means that you can ‘install’ Plex from https://app.plex.tv/desktop#!/.
epiphany and enable hardware acceleration.
paru -S epiphany gstreamer gsettings set org.gnome.Epiphany.web:/ hardware-acceleration-policy 'always'
epiphany and go to https://app.plex.tv/desktop#!/.
“Install” as an application.
Plex will appear as an app.