Why do you absolutely want to drain your battery faster than it needs to?
Because I'd rather not have to be stuck between two volume settings (iPhone sucks balls), and also I'd like to actually use some of the output power available and not feel like digital volume being so low and having that contribute to crushed SNR. But mostly, low impedances are scary, many times I've had loud content play on IEMs because it was 4/16 volume level set.
They can make the IEM sensitive, but I'd rather have higher impedance. Nothing less than 50, and more preferably something like 100. I hear this is trivial to do in design when making audio products, and it's mostly a decision, and not some sort of technical barrier or something that would -impede- performance.
How do you define "interesting engineering"? I can agree that many products are saturated that can also be said for many other types of product in audio. If it isn't tuned to a certain target you will say it's wild and unrefined, and if it's tuned to your preferred target you will say there's nothing new. What is your expectation for something interesting but also works well?
As saturated as the IEMs market goes, 64audio still has a few unique designs to have an edge over other competitors, for example their apex module (many IEMs don't even have module or bass/treble switch).
Talking about ergonomic, I think we figured out what fits the easiest for most people a long time ago, I just don't know why certain IEMs company don't go for that. Maybe it has something to do with their design aspects. Also low impedance fits well for many sources, I don't know what are the benefits of increasing impedance over the current setting.
I think IEMs are in a good spot right now but I really hate the pricing of many "TOTL" IEMs in recent years. I also wish they would stop hyping up (overpriced) IEMs cable as if they are some sort of a mythical improvement for transducers.
Tuning is irrelevant in totality of ergonomics aren't on point in my view. This goes for both headphones and IEMs.
As far as what's "interesting", it would simply be something novel, or against the grain with respect to features provided. Usually when a feature that isn't provided commonly is present within a product, that's an example of interesting engineering as it requires more effort than not when including said feature.
As far as 64 audio, they should worry more about their cables, and the pointless use of tons of drivers before they start adding bass switches (which isn't novel, it's been done by other IEMs in some form or another at the high end).
As far as ergonomics, they don't change anything because they don't want to bite the bullet on the cost with respect to R&D, nor paying for proprietary tip designs. Also tuning is seemingly easier with a straight tube going right in your ear that can be rotated as it's all a circle. To go oval, you have to have confidence your ergo's make sense. Their priorities are skewed unfortunately.
IEM's are in a boring place in terms of design (full metal IEM's are stupidity btw, heavy for no reason, and are prone to condensation that can damage/corrode some, while others suffer SPL issues after meshes get humidity forming on them when you take a metal IEM from listening outside, and setting inside a nicely warm room). The prices don't make sense from a value perspective in the slightest. They're literally testing the waters with how far they can push it without doing any work that remotely reflects the production cost. Any IEM costing more than what Meze put out doesn't really make sense to me. So anything universal around the cost of $1000 is about the limit (no IEM was better finished than that one). Unfortunately that IEM supposedly had bad tuning (the stem is hilariously massive and would be a nightmare to keep clean with no filter for some stupid reason), are made of metal thus heavy, and also like virtually every other IEM maker (aside from folks like SONY or Sennheiser that do their own designs and contract truly custom cables for their products), they all use cables that can be picked up pretty easily on AliExpress for a fraction of the cost. These ridiculous multi-weave multi-core "OFC" cables are all seemingly made by a source or two, don't really use some form of rubber jacket (instead use these stupid clear-view plastics) and weigh more than they have any right to. Some have a weave so thick, that the earhook area forms hotspots on the ear. Pair that up with a generally heavy-for-no-reason metal IEM, and you have the current crop of silliness.
So tbh, I think IEM's are in a horrible spot. There are a few nice ones. Most perform well enough. But it's just weird seeing the only movement come out of non-audio companies like Samsung and Apple (and Sony recently with their open ring IEM of sorts). Everything else on the market is just aesthetic pandering. Like you say, the hype makes no sense, nor does the cable worship. For headphones you have people using paracord to build custom cables. I cannot fathom on anyone can tolerate such material given how great the microphonic effects are (not audio microphonics, but actual microphonics that occur as a cable rubs your shirt or whatever). I see Sennheiser also doing this stupidity when offering their more expensive XLR cables for the HD800 for example. I'd literally pay them more money if they could just get rid of the paracord and make the cable as basic, soft, supple, and plyable as their HD600 line (you know, the cable that costs less than $20 if I recall).
Just makes no sense to me. This market makes one scratch their heads.