The suitability of a Pixelbook for use in the Real Estate field is highly dependent on the software and services you'll use in that capacity.
Chrome OS isn't particularly suited well for "vertical market" apps (software that is specialized for specific lines of business). That means that if you are going to rely on something like software that standardizes the gathering of information for RE listings, then you make have difficulty finding software that will run on a Chromebook.
I'm a fan of Chromebooks, and the Pixelbook in particular, but I wouldn't recommend one for your needs.
I recommend looking to forums that cater to real estate agents and see what hardware/software they use and recommend. If you plan on working for an existing agency, you might want to ask them what they use.