thanks for this, I was also in this situation, I got a xiaomi router and flashed OpenWRT on it, I then turned off the Wifi switch on the ISP router making it a modem only but I was still concerned about my internet data as it moves between my modem and their servers. your comment made it clearer
i should probably invest in that mullvad vpn now
i wonder how secure or private it is to use a password generated online. You should use a password manger instead. They have built-in password generators