Is there really any advantage to planar magnetics or electrostats?

[solderdude]

Yes that will help a bit. The problem is the bias voltage and AC voltage limit which can only apply a limited amount of force depending on the air gap.
For lower frequencies a larger excursion is needed which lowers the efficiency of the driver but could increase the bias voltage.
So there is a fine line between bias voltage, AC voltage, stator distance and noise/crackling and 'sticking'.

For that reason electrostats are much more limited planar magnetics.
Hifiman now also has very thing membranes with very thin metal traces on it and enough magnetic force and air gap electrostatic HP's can not achieve.

 

[mmmdc]

Planars are insanely low distortion (>80dB SID, even up to absolutely ear shattering SPLs) if built right (see: Audeze on a good day). Their big downsides are they're inefficient (these are headphones that will in general eat power like it's going out of style, part of why we're seeing 1.5-5w headphone amps now) and they can have really nasty upper presence to lower treble issues if they're not tensioned right.

Dynamics are way more efficient and way cheaper, but don't have the sheer SPL capabilities. Not exactly an issue in real life.

I'm not so convinced this is necessarily true.

In my opinion this comes down to outdated perceptions and small sample size.

A lot of people are only familiar with planars from a very short list of companies or straight up never questioned the "planars are hard to drive" narrative. DCA planars tend to be hard to drive, most newer Hifimans are kinda edging towards it but 92-95db/mW isn't outrageous and a lot of Audeze models are actually fairly efficient. LCD 2 Classic manages over 100db/mW, MM 500 is also quite efficient and so is the Maxwell.

Most planars aren't really "eating power" if you actually bother to look at sensitivity specs.