#1 Bluebooth connectivity to computers. If I was just using my phone they were mostly fine, but at a computer it was a constant fight to get them to connect, to work with whatever app I'm using, and especially when I'm switching back and forth between using them for listening to music or using them to video conference. This might also be partly because Linux is my main driver, but having to switch back and forth between high quality audio output for music and two way cell phone quality audio sucks.
#2 Having owned multiple pairs over the years, none of them would connect over Bluetooth while charging. Let me make my wireless headphones temporarily wired.
At this point I use an over the ear headphone with a mic and a USB DAC. I specifically only get phones with a minijack so I could use them with that too.