If greater salary transparency “causes resentment”, as a common argument goes, there is something wrong with the motivation system at your company. A healthy work culture cannot thrive on the lack of transparency about a fundamental parameter of the relationship with your employer.
The so called “salary based on value” approach in a market with strong information asymmetry is mostly a myth that does not take into account non-value related factors. You can be underpaid even if you overachieve.
If you are a highly competent introvert with insufficient negotiation skills, knowing what others earn (or offer) will level the playing field during a process that is skewed against you.
On the other hand, if you are already paid well above the average, more transparency will not hurt you. Companies know exactly what compensation distributions look like - after all they are the ones developing salary policies and doing extensive research on their competition. They will continue valuing you regardless of whether your colleagues know how much you earn.
If you are hesitant about discussing it openly, please contribute your salary information to anonymous databases and salary reports. Bring more transparency to the market. Reduce information asymmetry. It will benefit everyone in the long run.