I abandoned the thought of endgame. I have seen some posts of people spending $20K plus on their setup and still aren't happy. Of course, I also saw some posts of people out there very happy with their setup after spending $20K plus as well, but I had to do some self-reflecting. After some self-reflection and asking myself what I really want to improve on my system. I couldn't answer that myself and thus don't know what I am looking for in terms of improvement. So I ended my headphone adventures with EMM Labs NS1 (streamer) > Mojo Audio Mystique Evo B4B 21 (DAC) > Supratek Cabernet DHT 45 tube Preamp > Allnic HPA - 5000XL Amp > Onkyo A800 (for bass/fun music), Mysphere 3.2 (for something more natural), Susvara (for TOTL craving), and Schiit JR amp with Raal SR1a (for something pretty good and was too lazy to warm up the tubes). One headphone never really satisfied me as I get different cravings and each headphone has an addictive quality depending on what track I played them with. The only reason Supratek Cabernet DHT 45 tube Preamp is there is cause I got into speakers last year, but it's pretty dang good in a headphone setup as well. I did had the temptation of selling my current setup last month for the Allnic HPA-10000, but after talking with a couple of people, it isn't worth it cause then I will start craving upgrading everything all over again and I really don't want to upgrade everything again for my headphone setup lol. Plus upgrading for the sake of upgrading when I am already happy with my current gear seems like a rabbit hole I do not want to go down unless we are talking about fancy cables cause that won't cause too much disruption to the overall system.
So I guess I pretty much came to a stop in my headphone adventure and I guess reached my ending point for it for now and began my pursuit in speakers/room treatment. If endgame means pulling out of the hobby with the current setup that makes me happy, I guess I reached endgame. I see speakers as a different hobby than headphones, their presentation is really different to me which kinda sparks my interest in audio gears again because the most fun thing in this hobby for me was the exploration phase of finding that "favorite" headphone/setup. Finding my favorite headphones made the hobby a little boring for me, but listening to music is really fun! I'm glad I get to start over in the hobby again, but the twist is now I am dealing with speakers and the entire room itself. I hope everyone can find their endgame one day, it's really fun re-exploring your favorite tracks on a system you can be satisfied with. I highly recommend you re-explore your favorite tracks with each upgrade, it will make this hobby more satisfying in the long run.
As for headphones I went through before finding my favorite 4 (used to be 5 but temptation got me selling it and hella regret it lol), I went through a lot of headphones in terms of owning and demoing at a audio show or in shop. I liked about 95% of the headphones I tried and could be happy with a lot of them if I never heard better. I think the key is to not hear anything better and you'll be ok with whatever endgame you'll end up with lol.