I was going to going to ask this question because Steam Flatpak was listed as last being updated May 2023, but they just updated it yesterday. That’s still about 9 month between updates.
In general if I am on rolling release like OpenSuse Tumbleweed is my Steam package and Mesa drivers going to be more up to date then what the Steam Flatpak provides or are they updating the Flatpak and dependencies more frequently then the Discover app is suggesting?
What distro are you on?
Ubuntu 23.10
The Flatpak is probably going to move faster but the trade off is it is harder to configure some things until you get a handle on Flatpaks.
Up to you ultimately.