If your list is mostly in those places, the third column is not optional for you in the way
it is for someone applying to the Netherlands or Germany. Every item on this page says where it
applies.
None of that is a reason to do less. It is a reason to do the things that matter for the right
reasons: an Extended Essay because it tells you whether you like a subject, CAS because it is
interesting. The worst outcome is a student who spent two years building an application portfolio for
a system that was never going to read it — or one who assumed nobody reads it and applied to five
places that do.
Three different things get muddled together under the word 'preparation', and the difference matters enormously. Something officially required decides whether you can apply at all. Something used in selection is weighed when places are allocated among people who all already qualify. Everything else is useful preparation — genuinely worth doing, and with no effect on admission. A CAS project does not get you in. Nor does an Extended Essay topic. This site will not pretend otherwise, and knowing that saves you a great deal of misdirected effort.