These OLED displays (SSD1306) are quite reliable and long lasting. This Russian guy did a burnin test for over a year of
a bunch of the displays:
It seems that their life depends on brightness and time, not how frequently the pixels are changed.
If you do replace the OLED display be careful to note positions of the power pins on the 4 pin header connector.
The power pins are reversed on a lot of the displays.