Hmm interesting, I would have thought digital forensics would be a space that lots of FOSS would exist in.
For me, it’s Discord and Steam. There are some good alternatives for Steam in the sense of being a game launcher, but not with all the modding and friend join features, which I use quite a lot.
Discord is worse for me though, because Valve is a least a FOSS friendly company, but Discord isn’t the same. all my friends and family are on Discord and have no interest in leaving. There aren’t any FOSS alternatives that have all the core features that Discord has and work well.
And contrary to a lot of FOSS enthusiasts, I actually really like Discord, it works well most of the time for me.