I practice yoga and pranayama but I think for many people decoupling the breathing exercises from the spiritual side encourages them to try things they would have otherwise have shunned. I also think many of the secular breathwork practitioners aren't being deceptive - many of them are very open about their influences - Wim Hof had certainly talked about his time in India etc. What is interesting for me is understanding more of the science so we can figure out which parts of these practices matter for what and whether some parts are extraneous.