I like having the columns I am working on at the top of my list of data (the bit bottom left in the UX). However new columns are at the end of the sheet (last column) which requires a lot of scrolling), or get hidden in the mass of columns.
I have one sheet with at least 300 columns (I pull in single value columns for language strings - one way to use up lots of columns).
It used to be hell on wheels to move the columns across manually (at least it is doable).
BUT then I remembered I can zoom out on the browser (+ / -) and then I can see loads of columns at the same time, making it faster to move columns about.
I hope this tip helps!