I used to have IEMs for my plane trips from the £150-300 price range. Even though I had custom sleeves which fit more than one type of universal IEMs (IE80, Cardas A8, Flare R2Pro) the comfort was just ok compared to my full sized headphones. Wires and an external DAC (Chord Mojo) made audio on plane trips a bit of a hassle. Since I upgraded my home system I realised that my portable rig will never match that sound quality. Hence I started to look for a more comfortable option for my travelings. (40-50hrs on plane, 40-50 hrs on train in a year.) The most simple and best wireless sound according to my experience is from android 8.0 (LDAC) to the Sony 1000XM2. The sound is fairly balanced, good/listenable enough even after coming from much better desktop rigs. It is a compromise, but 6-8 times in a year I am happy to make this compromise. No wires, no amp/DAC stack with my phone just acceptable and good enough sound for the flight. I prefer the 1000XM2 to similarly priced IEMs. Sound is equal or better. Even though the earcups get sweaty and warm after half an hour they are still more comfy than something stuck in your ear-holes. Sound is equally good than similarly priced IEMs, but being a headphone it is more comfy and pleasant.
If you are an absolute sound quality nerd, and you are happy to stack your phone with an external portable amp and don't mind IEM wires, than you can probably find slightly better sound for £2-300. (Plus the amp/DAC you use). If you want to keep things simple on the go and value comfort as much as sound quality, than the 1000XM2 might be the sweet spot of compromise for you too.
They are good enough for flights or traveling. The touch controls and LDAC makes them the best wireless NC headphones to date. For £230 what I paid for them they are a good pair of headphones for flights when I am away from my beloved home rig and very comfy not using wires and external audio equipment beside my phone. [Just make sure you tick 'optimised for audio quality' instead of 'best effort' (adaptive bitrate) in android developer mode.]