You have shown that the DO statement is powerful, and also that it can be confusing, particularly for those more familiar with other programming languages. For maintainability I prefer simple, easily understood code. For that reason I avoid the DATA step and loops if possible and use PROC SQL.

The picture of loops is Tiger and Turtle. It is one of my pandemic cycling destinations - I was there on Monday. More: https://de.wikipedia.org/wiki/Tiger_and_Turtle_%E2%80%93_Magic_Mountain (also available, more briefly, in English).