The thing you lose when doing away with the Cerbo is the larger ecosystem. BMS is just a piece of it. The wakespeed reads directly from the BMS, but it is monitored by the Cerbo. The cerbo also controlling the solar controllers, monitoring loads. Plus, I use it to monitor my tankage (Fuel, Potable Water, Sewage, Bilge), monitor my boat sensors remotely (Is it worth sailing today? lets check SignalK and see what the wind sensor is reading!).
And all of this is remotely accessible through Victron's website, which allows me to remote control it and monitor things while I'm not on the boat. It's a very much worth it in my books.