I had to think deeply about what you said here... Took me a long time to gather my thoughts, LOL!
If I remember correctly, back in ARR, it wasn't the Lucis that was though. It was the Master Book 2 (containing ARR 4 star recipes for i110 battle gear) that was the toughest to acquire. One needs to unlock Master Book 1 to get the recipes for things like "Calibrated Rose Gold Cog", and then one had to HQ the Cogs to obtain Master Recipe 2. You could just buy items to exchange for Master Book 1, but I remember most players had huge difficulties in HQ-ing the Cogs, thus only a handful of master crafters had access to Master Book 2's 4 star recipes, and we were selling the i110 crafted gear exclusively on the MB. When the Master Book 2's were released, Artisan Offhands were also released. I chose to skip it, and acquired all the books with just Militia Offhands, LOL! And then tackled on all those 4 star recipes with just Militia Offhands (eventually I did make the switch to Artisan Offhands)! That was good old times!

And only after that, then Lucis tools were added to the game, and surprisingly, people still had trouble with those Cogs even after having Lucis.
That kind of locking recipes behind bars had not happened since then. Since that day, crafting had been made easier and easier each day. Some people called it a "decline" of the crafting game. Others supported it, as more players are able to access endgame crafted gear.
We all know the benefits and problems of making certain recipes only available to a small number of crafters. I'm not going to comment here. There are obviously two sides for the coin. Imo, the biggest issue is that ONCE IN AWHILE, the coin needs to be flipped to balance the benefits and problems. However, as I mentioned above, the coin has been on one side for a very extended period of time... (basically since 2015).
I didn't call out because I've seen many call-outs from other crafters before, such as those from RothTrailer. And yet, almost every time, SE would dismiss such call-outs for harder recipes. There was one time in Stormblood that they released Special 2 Star Recipes (Snailfish Oil etc). Those were quite hard and fun, but they nerfed them 1 or 2 patches later. I eventually kind of gave up. But you're right. Deep down I'm really bored, and every day, I'm waiting for something to happen, and yet it never comes. Maybe it's time for me to take a step up, and voice my opinion.
Locking recipes behind bars is one thing, but having difficult recipes to fiddle with is another issue. I think SE actually can separate the two. Many suggestions that I have seen before supported this idea. I also support this idea. Perhaps I'll make a thread in regards to this. ... Gosh, this feeling reminds me of the time BEFORE I wrote my first crafting guide... That was the time when I thought, "Gee, perhaps I should just do something about it, and write out a guide for the people". De Ja Vu here!