I’ve only gotten 3-4 GB recently, so much better than yours LOL
It is clearly only the Safari extension that does this. I’ve continued to use Bitwarden the app, which doesn’t have many of the convenience features of the extension. I thought they said they were going to address this, but they never have. I"m using an M1.
I see no such behaviour on Sonoma 14.3.1 on an Intel Macbook Pro. BW is using about 400 MB total, app + Safari components including GPU helper. It is not increasing. BW app and Safari have both been open for days.
I did not do a with/without speed check now. One done for other purposes a couple of days ago showed no deterioration from pre-BW days.