I am not comfortable that signal depends proprietary google library. However, I find that Molly lags significantly behind signal (around 1 to 2 weeks, so maybe not as significant as I thought), but I am just concerned that if there is a security fix in signal, molly will not be able to react as fast.
I am also quite frustrated with the general lack of communication from the signal team (for example the lack of communication regarding username). I doubt they will have the good will to help molly when there is a critical security fix.
It is frustrating that signal no longer seems like the gold standard for privacy any more; unfortunately, all my friends are on there (ironic, isn't it...).
For some reason I also was able to get most of my friends and family on Signal and just a year later I set up Matrix and now nobody wants no move anymore.
I guess I was just persistent and very lucky that WhatsApp did some changes so some of my family members were upset and then a group of friends were looking for something to include people who are not on facebook so I proposed it, etc.