The “best” CGM is a very personal thing. Some people are more suited to Libre and others more suited to Dexcom. For example, whilst Dexcom is often considered the better one, the Dexcom G6 was far less accurate for me. I have not tried the Dexcom ONE but my expectations would be the same as it is basically the same thing with some dumbed down software (e.g. not possible to use a follower app).
The other things to consider with the Dexcom is that it is supported on less phones and, unlike Libre, if your phone is not on the supported list, the app will not install.
In addition, it has a separate transmitter and sensor so you have to commit to a longer contract with them.
I assume with Libre you have taken into cons the limitations of all CGMs like bedding in time, compression lows and varia from “normal”.
The other option to consider is using a third part app to read it such as xDrip, Shuggah or Diabox. The great thing about these is that you can calibrate the sensor against finger prick readings.