For those die hards who find sudo less to your liking it may be
tempting to try to convert Ubuntu to the Debian norm, but in my
experience it is not worth the effort.

I have added a root user in Ubuntu with a separate password, but due to the way
the groups are set up it becomes very confusing. One application may prompt for
one password and another may prompt for the other one which only succeeds in
making the whole exercise confusing to my way of thinking. You can probably go
to the user admin and change groups manually, but it is not so easy to do this
if you don't know what the groups do and you can really mess us your system if
you make a mistake.

It took some getting used to sudo when I switched to Ubuntu, but it works better
in Ubuntu than you might think. If you want to get rid of sudo, it is probably
better to switch to a distro that does not use it such as Debian. However, a
little research will reveal that sudo is as secure and a little practice will
make it second nature.