Over the last 7 years, that post never resulted in any action by the BitWarden team, and was recently closed as “stale”.
Firefox is now at v149, and the correct URL to observe extension memory use is now about:memory.
Will someone on the BitWarden team please take a look at why BitWarden uses so much RAM, and if something can be done to reduce this amount? As I mentioned years ago, please prioritize performance, within reason.