While Arianism remains strong in christendom, I think its heyday is past... with the exception of Mormonism.
why?
people generally say that mormons have a genius for organization. This may compensate for what evangelical denominations say are theological problems which have crushed more poorly organized denominations.
most of the german churches for example embraced arianism in the 19th century before they died in the 20th century. arianism left them too weakened to fend off the attacks of the atheists. For example, Nietzche’s father was a german pastor who embraced arianism. It is said the most popular books in the german trenches during WWI were books by Nietzche. In the US trenches the most popular book was the bible.
liberal denominations in the USA today like the PCUSA that have informally adobted arianism are losing thousands of members annually.
People said that Mussolini made the trains run on time.
What I find interesting in MORMONism is that their most SACRED rites are NOT found in ANY of their scripture.