Words with Greek roots that end in -is or -es generally use the -eez suffix. e.g. analysis -> analyses; thesis -> theses
In the case of Latin, it's -ix or -ex. e.g. index - indices, appendix - appendices.
There are of course exceptions and outliers (suffix -> suffixes; octopus -> octopodes!?), but words like "process" and "bias" do not fall into the categories mentioned, so there's no reason to use the non-standard "processeez" and "biaseez". Unless - IMO - you want to sound like a snob... Think about it - how does one pronounce words like "successes" or "princesses"?
One could argue that language evolves - this is true, but in general language evolves to have simpler rules with fewer exceptions rather than the other way around.
Stop, let's all try to stop the madnesseez.