I first tried za-zen after reading about the method in a book which my dad gave me. He had used it sometime in the 70s but had since became scared of meditation because of some later episodes. This may be related to what OP said, but in his case I also think it had to do with a strong fear of facing himself and his own inner world. Sometimes I would feel like he was completely detached from reality, and that he used this self-imposed insanity as a way to shield himself from the consequences of realizing what he had done and caused, and how his actions had lead to negative outcomes for himself, which he didn't want to recognize though it was visible to absolutely everyone else.
A strange way of hiding in his own mind. Any form of meditation at all would probably turn into a horror show for someone like this, as the only way to avoid insight would be to constantly aim outwards and to engage outwards. His response to any topic at all relating to the meaning of life, death and such, would be to simply leave the room, or if this was not possible, stare into the distance with a hint of panic behind the eyes, before saying something almost otherworldly delusional, and suggesting some physical activity to avoid thinking, which he considered dangerous.
When reading the book, the concept of satori was described, and the reader talked about having achieved this state of mind. After trying za zen once, I did the same thing, the description matched, and since this was said to be the goal of the practice, I didn't do it again after. I tried a few times but just remained in the same state which instantly appeared, so I just figured that was it and that zen had nothing more to teach. I now realize the point is to stay in that state of mind for meditation, not just get there once, which the author and his teachers seemed to propose, but I so far haven't had a reason to use this practice for anything other than as part of karate, where it can work to solidify what was just practiced. This may be what it's form, a process to reset the mind quickly.
When I later started learning FG meditation, it was just torture, that exercise in lotus position for one hour was also said to be painful to remove karma, and I forced through that daily for a few years, until I made a breakthrough and the motivation for doing the exercise just fizzled out. I guess I did achieve what it was meant to do, after that time I don't feel motivation to do it, and it's not particularly painful either, mentally or physically.
I didn't pick up any meditation again until after Covid when Sadhguru started marketing himself more online. I did his introduction practice for 40 days, and there was an effect which caused a ripple through the body on day 40, after which the meditative state became easy to achieve and uphold. After this I've used quarter lotus position for meditation during sessions of around 1 - 1.5 hours or shorter if I don't have that time, and it's not hard to maintain. The effect of hatha yoga is contrary to the earlier forms I did, rather pleasant mentally and not physically straining either, but only after I went through those 40 days. There seems to be a threshold like this for meditation, as I've experienced it for each I've done, with different levels of difficulty. With FG it took 3 years.