Prices for (electronic) hobbies will never go down again, look at the GPU market. The last somewhat reasonable priced highend GPU was the GTX 1080ti, Nvidia went all out because they feared that AMD could beat them. It was expensive, but worth it. Since then prices went full bananas, and the problem is that unlike with headphones, you kinda want to buy a new model every 2-3 years. I'm sort of happy that the TOTL's in hi-fi will stay relevant for a very long time. A Susvara 2 won't be miles better than the current one, even if it comes out tomorrow. Of course manufacturers hype up new stuff, but it rarely really beats the old one 100% nowadays if it's in the TOTL realm. Look at the new Utopia, a sidegrade for 1k more. A fantastic TOTL amp or headphone now will still be fantastic in 10 years.
The Abyss guys did something extremely rare, they built a headphone from scratch without caring about the price and did not have any (cheaper) models to begin with. It's a miracle (of engineering) that the 1266 ended up on the same level next to the Susvara. They saw that it sold very well despite being 3k, and then they upped the price, twice. Of course like with the Utopia, making that price change with a new revision (Phi, CC, TC) made it a litle bit more palatable for the customers.
On the other hand, the tech is trickling down, so you will always get better stuff at better price points. Look at the Hifiman HEK or Arya models, you get (mostly) better sound for the same money than 2-5 years ago. But if you want to get the best available, it will cost you, for a reason. We seem to have reached somewhat of a ceiling, of course there are the ultra 3 expensive Estats, but that's another story (and i personally disliked the Aperio when i heard it).
The more TOTL something is, the longer it will stay relevant in this hobby, which i personally like. Of course, companies and reviewers want to create hype so they can show off their new shiny toy, but time will always tell (and told!) that some hypetrains will get swapped out for another one.
In the last few years, what were the true Susvara (2) contenders?
Audeze LCD-5 -> Divisive signature, also very resolving, still not quite Susvara level (personally i want the old Audeze sound back, like a modern LCD-4).
Abyss 1266 TC -> The polar opposite sound signature, a true competitor that's on the same level, it got that "king's place" next to the queen's throne. Different, not better.
Warwick Bravura -> Some say it's better, some disagree, so purely subjective (i prefer the Sus). Also a whole system, can't sidegrade / play around.
Utopia 2 -> Sidegrade (or minor improvement) to the OG one, every reasonable reviewer got that, probably the best DD we have in headphones.
DCA TOTL's -> Where are the dynamics my guys? Harman tuned with details is not everything. I was disappointed.
The newest Hifiman HEKSE model -> Gets closed, but doesn't fully reach the Susvara (let's be honest, Hifiman would be dumb if it was better).
Charybdis -> A mix between the Sus and the 1266 from what i've heard, i would love to test it more, but it's 740g(!) and has weird dangling connectors, also people state that it's not better sounding, just (again) different. I was very close to getting one, maybe some time in the future, maybe i'll wait for another revision. It's the latest competitor.
Stax, various TOTL models -> Some say more details, but you seem to have to spend insane amounts of cash on the amp for "okish" dynamics, otherwise they are well below standard planar level. I was shocked how bad the dynamics of the X9000 were when i heard it at Munich. Experts in the Stax thread said it wasn't amped properly.
Do i dare listing the Spirit Torino Valkyrie? -> Extremely divisive, i heard it very briefly, was not for me, i won't spend that much (even used) just to test it. Very few people prefer it over the Sus, but objectively better? Lol.
ZMF Caldera -> Fantastic headphone, but it's one notch below the Susvara.
What's on the horizon? Maybe Modhouse Tungston, we don't know. Zeos said that he has a review for patreons up while the last changes are being made. Almost on the same technical level as the Susvara while being cheaper? Maybe. Better? Very unlikely.
If there is something coming out that's truly better, let's just say, a Sennheiser HE-1000, than it will be priced at ~10-15k. We already had the Shangri-La Junior which didn't uniformly surpassed the Susvara.
Making a better sounding Estat (while fleshing out the typical Estat problems like bass and dynamics) seems to be extremely hard, often internal EQ is used.
All the listed planars do not clearly surpass the Susvara, so there's probably not much room left (if any).
It seems that dynamic drivers can't compete on the highest technical level.
Of course these are my thoughts, but you can use some logic and think about why things are (still) priced how they are (while on some things you can't argue with logic, hello Spirit Torino).
Thanks for reading that wall of text, Cheers!