"Clean" layout seems to have disappeared in 3.0.
This was a very important layout to keep Spaces separated.
This helps to keep your view distraction-free, which is especially helpful for people with ADHD or people who have trouble focusing or getting easily distracted.
Being able to see all Spaces at all times with all Space names is incredibly distracting and is visually overwhelming.
It is also not a benefit when your Spaces are not related to each other - I don't want to see my Spaces together because they are all completely different areas that do not overlap.