Reader Matthew chimes in with this key point:
You’re missing one component in your discussion of why people use lye for pretzels. I learned this a few years ago when I compared several of the alternatives you mentioned against the lye-dipped pretzels. Only lye-dipped pretzels really taste like pretzels! It is a difficult flavor to describe, but immediately recognizable as “pretzel.” The alternatives lacked that “pretzel” taste, so the use of lye goes beyond appearance and texture, and directly to the heart of the matter–taste!
Well said Matthew. Thanks!