They're not going to fail, unless you have an insanely high bar for success, and they're not going to sound like shit either. Apple wouldn't just accidentally release a terrible sounding headphone product without having people familiar with headphones listen to it.
The arguments floating around here are pointless. Will you be able to get better sounding (particularly wired) headphones for less money? yes. Just like you can get a higher performance laptop for less money than a macbook, and just like you can buy a discrete graphics card that performs better than integrated graphics (analogy to wireless w/integrated DSP and amplifier, vs. discrete)
Is the point here to have the best sounding headphones? no. There are for daily/practical use cases and pleasantly usable performance for dedicated listening and entertainment. They are primarily headphones for "routine use"/work, e.g. when your listening to music + doing some task, then taking a phone-call or joining a meeting. The same use cases people currently have noise cancelling headphones with built-in or inline mics.
For example, Bose QCs are very popular for that use case, and cost $300+. I use them for daily work and travel, and I'm an "audio person", with completely different setups (plural) for audio quality use cases, well aware that the Bose QCs are not "$300 class" headphones quality wise.
The Apples are more expensive than the QCs, but even from pictures and build materials immediately crush the QCs in build quality. My guess is that they will also beat them in sound quality. Yes they're more expensive, but tbh for the target use case, it is not difficult to justify cost for something you use 8h a day. Of course anything expensive is not in everyone's budget, but considering the target market, people talking about $200-less headphones are not priced out of the headphones, they're just trying to save money.
So, true to Apple, the increased cost doesn't really hurt their addressable market, and instead positions them a status symbol where it is actually important that they cost more than the competition. Yep.