Most people cannot. Anyone using Spotify has probably never even gotten into the audio quality settings to change the bitrate as it defaults to Auto. Auto shifts the bitrate down unless you're on WiFi and you've set it to max quality. If you're on mobile data it goes way down. I've had friends who are listening and it sounds awful, you can hear the aub-mp3 quality compression. They never care when I point it out.

I'm not arguing about what is technically possible. I'm arguing about what is practically possible: Samsung (biggest market share) supports LC3 for example, but they can also break it and replace it with their custom codecs to lock people into their ecosystem. Making Sony LDAC the only real choice, and there's no telling when they will break that too. This means that in practice, only SBC and to a lesser extent AAC and SBC-XQ are the only codecs you know for certain will work.

Only if both your device and your earbuds both support aptX Lossless, which in practice means it almost never gets used because Samsung (holder of most of the market) does not pay for the licence or enable it in their phones, and the Chinese brands only do so for specific tiers and processors.