Trying to get everything that's needed for it and following the protocol can be a hassle for sure but what makes you think that it's the slowest and most painful method or the most difficult to find in the EU? It's easier to obtain (or already have) something to hang yourself with and I guess you can jump from practically any tall building but I think it's easier to access than inert gas and/or other poisons and drugs used by people to CTB. As for it being slow and painful, from everything I've read, it usually takes people 20-40 minutes to go unconscious and the rest doesn't matter since you won't be conscious of it anyway and you just need to make sure you won't be found for a couple of hours. And painful - for me the worst part of it is the possible vomiting (since I have severe emetophobia) but most people don't care that much about it so I don't see how that could be excruciating. I guess there's the possibility of seizures too but all in all it seems bearable considering you get a way out. Choking, drowning or bleeding to death seem way more painful in my eyes.
I might sound argumentative but in the end of the day everyone should decide for themselves what method they prefer and what would work the best for them in their opinion. I'm not super enthusiastic about taking SN, if I could choose another method without any restrictions I'd definitely not go with SN but I personally see it as the only option I have. Technically I have two other options - hanging and jumping, the ones you mentioned.
There's no way I could make myself jump no matter how much I'm suffering, I'm afraid that I won't die immediately but instead break all of my bones and die in agony and I also don't want my body to get completely messed up like that, I don't wanna traumatize my mother or anyone who finds me for that matter and I've heard some pretty horrific stories from my parents and friends about the jumping cases they've witnessed/know of.
And hanging - I've tried it more times than I can remember, I can never get it right, it's extremely excruciating for me and way harder to set up than SN. Less than 2 months ago I fully believed that hanging would be my method and I thought it'd be way better than SN, I truly wanted to make it work somehow but I just couldn't and currently I'm at a point where it's impossible for me to do it for various reasons.
SN might go wrong too and I'm kind of expecting it considering my bad luck but it's just the only option I have left and I think that goes for a lot of other people too. Other positives in my opinion that I didn't mention - you can do it in the privacy and comfort of your own home and it doesn't really leave a mess.