I'm baffled by the way some people think that because they don't need a feature (like SD slots or physical function keys) then nobody needs that feature and thus it should be expunged for everybody, let they suffer the appalling ignominy of having a computer with a slot or key that they don't use.
Personally, I like the sound of the touch bar (but I'm using an iMac at the mo', so it will have to wait until I upgrade to Catalina and can use an iDevice). However, I'm also aware that there are people who spend all day pounding a particular pro application and have memorised the function keys. They could have found room for both - especially as nobody was asking for the trackpad to be made even larger than the largest-in-the-business one in the pre-2016 MBP.
I'm not one of those pros. However, I've got a phone that takes SD cards. I've got 4 Raspberry Pis that take SD cards. I've got a Fire TV that takes SD cards. I've got a module in my Eurorack synth that takes SD cards. Other people have GoPros, dashcams etc. that take SD cards. You can get low profile fit-and-forget SD cards that are perfect for (say) storing a music or photo library on without wasting fast SSD.
Sure, there are adapters. Know what's better than needing an adapter? not needing an adapter! Know what the downside is of having a (tiny, cheap) SD card reader in your laptop that you don't use? None!