information was not available as it is today so refuting a heretic was more difficult.
What “new information” is now available to Catholic clergy that would make it easier?
the cathars, an evil religion if there was ever one, were snuffed out by courageous catholics. think of how many people would be spared from suffering if mohammed or joseph smith were killed for thier heresies.
“Think of how many people would be spared from suffering if [Christians] were killed for thier heresies”
“Think of how many people would be spared from suffering if [Catholics] were killed for thier heresies”
It all depends on who gets to decide on what is heresy.
As to whether it was intended to be painful, see
leedstrinity.ac.uk/histcourse/reformat/maincore/past8128.htm
"In the case of Thomas de St Paul (Paris, 1551) the victim was dipped into the fire several times and after each “taste” of the flames asked whether he recanted, in which case his life would be saved. This “dipping” into the fire was, indeed, a fairly common practice and left open the possibility of last-minute recantation. Some victims were strangled before burning, though it is not always clear why. This was generally the practice with condemned criminals who had provided useful information for the court, thereby rewarding “grassing” while preserving the spectacle, and could thus be modified into strangling as a “reward” for recantation. For example, it was ordered that Jean Michel (Bourges, 1539) would be strangled if he retracted his errors, and Claude Le Painctre (Paris, 1541) would be similarly treated “after having felt the fire a little”, while Pierre Chapot (Paris, 1546) would be strangled if he said an Ave Maria on the scaffold.
In other instances, however, the reasons for strangling are not specified. In the case of a group execution at Paris in 1558 the one woman involved was strangled and the men not, but usually the sexes were treated alike. Nor was the strangling necessarily done thoroughly, as if that might detract from the spectacle. The anonymous old man at Paris in 1542 was thrown “half-dead” into the flames, while when a cloth-shearer was burned at Montpellier in January 1554 he was both incompletely strangled and placed on a fire which refused to burn vigorously. Whatever the theory, the church and secular authorities could turn a blind eye to such “accidents”, which served to make the drama longer, more grisly and therefore, it was hoped, more effective. In the 1550s the practice appeared of covering the victim’s body with grease and throwing sulphur on to it as it burned, thereby making death longer and more painful. Crespin first records this in 1552. Such suffering emphasized the ideologically constructed community’s vengeance on the disturber of its order. With the painful and thoroughly deserved total extirpation of the outsider the crowd was supposed to go away content that this order had been restored and the outsider expelled socially and condemned to eternal damnation. The threat had been contained by the ritual of degradation, expulsion) and destruction… "
Some would have their tongues cut out or be partially dismembered before being burnt
Yep, sounds like the goal was the most “humane” and “compassionate” choice available to me

--that argument is rather akin to the one justifying slavery–that slaves enjoyed slavery and were consistently well-treated by their masters, and did not want freedom. Might have been the case in an extremely few situations, but far from an accurate representation of the overall situation.