It works better for searching, it works offline, catch-all addresses just work with correct from address when replying, backup and archiving, can move mails from box to box without sending.
I also use roundcube, but only to read mails. If I want to reply to a catch-all mail I have to create an alias which is super tedious.
Just let terrorists do the transactions so you can follow their cash flow. This is only hurting people who need to make some large down payment legitimately and now have to jump through hoops.