Roman Catholic Indulgences

On 25 Sep 24, @MrCasey62 on X re-posted this meme from @cjohnsonn0311 above with the following response:

“Just going to keep reposting this every time Protestants lie: The Catholic Church has NEVER ONCE taught that indulgences forgive sins. This is exactly why so many Catholics think Protestants are simply unintelligent.”

I replied to @MrCasey62 with the following:

Sir, I’d like to respond.
It’s been well said that “He who frames the argument wins.” You’ve put forth a clear frame here. "The Catholic Church has NEVER ONCE taught that indulgences forgive sins." I'm terrified by the power many seem to think they hold to simply redefine the past at their pleasure.
I agree that there's a nuance to the idea of indulgences that many misunderstand, and I don’t want to intentionally misrepresent or certainly not “lie” about anyone’s doctrines, but it's not as far off as you're framing it to be. If I announce a “free hamburger…” outside my store and then in fine print on the inside counter put “…with the purchase of a soft drink” it’s false advertising, but not false advertising…if I can reframe it how I wish. The Catholic Church does teach something else regarding indulgences other than a blanket pardon of sin or the promise of future pardon for it, so the meme you responded to is likely more sarcasm than anything else, but the premise is not far afield given the church's teachings. One Catholic source gives a nuanced definition similar to one you present saying "An indulgence is the extra-sacramental remission of the temporal punishment due, in God's justice, to sin that has been forgiven, which remission is granted by the Church in the exercise of the power of the keys, through the application of the superabundant merits of Christ and of the saints, and for some just and reasonable motive." (https://www.newadvent.org/cathen/07783a.htm). So, it's not a forgiveness for sins, per se, it's a removal of purgatorial punishments for sins already forgiven...if one is in good standing with the Catholic Church already. There is a nuance here. There is a difference here, but it just comes down to field semantics.
Sir, none of us get to ignore history or just redefine it away. Rome's abuses in the past on the doctrine have done more to create confusion than anyone’s ignorance. Remission of purgation of any sort, being that purgation only regards those whose sins are not yet completely removed, is not at all a far cry from believing that an indulgence straight up forgives one’s sins. There's a nuance, okay, but it's not like it's a Grand Canyon-sized chasm. It’s more like five feet wide. You do a thing, walk up some stairs, walk through a doorway, etc. and pay a customary fee and, if you're a good Catholic doing it in faith, you (or someone you know) get(s) blessing(s). That's all intact despite the nuance you’re highlighting. And it's still a dangerous falsehood. Indulgences have no basis in Scripture at all.  
When St. Peter's Basilica was to be built just about 500 years ago, indulgences were sold wholesale under an auspice you don't get to simply disregard. They were sold under the pretense that they could a) reduce one's time in purgatory, which you agree, and b) that they could affect one's loved ones already in purgation. Were other things understood alongside these ideas that weren’t papal teaching? I imagine so, yes. Could much of the confusion be opposed to much of cherry-picked/retained “official teaching?” Yes. Okay, but wrong beliefs about indulgences didn't come from nowhere. They came from Rome’s actual teachings. It violates the modern sensibilities of modern far western Catholics, but it’s history.
The Reformation was tipped off by the gross abuse of indulgences in Europe. The 95 theses of Luther (which I'd bet my bile duct you've not read) center on indulgences for a reason. And Luther was still a loyal priest when he wrote them. The treasury of merit is a terribly false doctrine with no basis in the apostolic faith. The abuse of indulgences is indeed an embarrassing abuse of the idea that most Catholics today would even say was wrong. I’ve spoke to priests who fully agree with that statement.
Indulgences are a dangerous idea, whether abused or not, that center on the un-biblical idea of the treasury of merit. It's an extra-sacramental exclusive sacramentalism. Period. And they should not be practiced.
Indulgences are still practiced today, they're just not nearly as abused. What they (falsely) offer are blessings for observances...customarily observed with alms giving. It's easy to see the confusion many had and have regarding this un-biblical idea. It made millions. I’ve been to the Vatican. I’ve been in St. Peter’s. The tourism today makes far more than the indulgence ever did. The confusion on the matter is a fact, okay, but it’s not the confusion that’s the problem, or even the abuses of it that are, it’s the established idea of an indulgence at all that’s the problem. It’s the un-biblical idea of the treasury, the keys, the papacy. But that’s clearly a wider issue. With respect, we’re not all ignorant or liars, we just deny indulgences in every sort.