I do accounting research. My human-subjects research involves surveying practitioners about their jobs, interviewing them about their experiences, and conducting very simple experiments online that ask them to make decisions. There is virtually 0 real risk to any participants of my studies. IRB does always give my studies "exempt" status, but it still has to be reviewed. And they will pester me about different things like where will store our data (Onedrive is fine, but dropbox is not for some reason). This process will typically take a couple weeks of back and forth.
Yet I have a friend who participated in a Kinesiology dissertation study where they were asked to do extremely strenuous physical activity. He fainted(!) at one point from the activity. And it seemed to them that there were relatively few safeguards from that happening. Now, I'm sure that study did have IRB approval, but it really got me thinking... are we really scrutinizing studies optimally?