Wired and a dedicated device will always be better of course if you can manage. I’m currently going with wired IEMs attached to a Bluetooth DAC/amp that connects to my phone. There might be some quality loss indeed, but I’m probably not going to notice it in the outside noise anyway. Still, I can use the DAC connected via USB too if I insist on lossless - but it’s a bit cumbersome with using my phone attached to it. It’s fine with a player that I toss in my pocket and maybe hit play/pause from time to time, but with a phone that I’m using way more often it’s inconvenient.