I don’t see it.
The High Sparrow, Like Stannis, was a man who was doing his duty out of devotion, not self aggrandizement.
He achieved a life of wealth and luxury, which he rejected and pursed one of penitence and service.
Yes, service as he viewed it, that included making sure everyone else yielded to his will...whether they yielded due to being broken by torture, or by soft spoken words, made no difference. That’s not service.
He was just as much a sadistic bully as the rest of the wretched lot, he was just more soft spoken. His “relevations” and threats may have always been delivered in subtle and gentle tones, but there were always armed fanatics at his back as he delivered them.
He was no different in any way, from the rest of the lords and ladies leading their armies to grow their power and influence, other than he had no high birth or money to gather followers, so he wrapped himself in “religion” to gain his loyal army.
If those you claim to help, get their “help” with your sword at their throat, you are not offering help or service, only subjugation.