I never considered the brightness an issue. I actually like to keep the brightness as low as humanly possible to avoid wiping out my eyes. My rule of thumb is, "no brighter than a piece of paper"....i.e., I hold a piece of paper up next to the screen and lower the brightness down to match it. 100% brightness is more of a Vegas demo feature to me.
For background, I originally bought my 2018 Macbook Air out of frustration that there was no new update to the 12" Macbook. I just wanted something light for my commute on a bicycle, but refused to only have 1 USB-C port, so I got the MBA. As it turns out, I find the keyboard so much nicer to type on than the one on my wife's 2016 MacBook Pro, and it surprisingly handles most of my video production needs while on the go. I eventually move these movie projects to a more powerful iMac, and that's ok with my expectations. The only weird thing I've found is how slow it handles editing photos in the Mojave Photos app. Adjusting sliders for shadow, definition, etc... used to be a snap in Mavericks, but it's molasses for Mojave. Other than that, love the MBA!