Why was the limit value for the protective conductor resistance changed from 300mΩ to 100mΩ?

With the standardization (EN0701-0702 → EN50678, EN50699), the determination of the limit value for the protective conductor resistance has changed somewhat. For cables with a cross-section of up to 1.5mm2 , the limit value of 300 mΩ continues to apply (for cable lengths <5m).
For larger cross-sections, however, the limit value must be determined by calculation, whereby the smallest possible limit value for single-pole lines is now 100 mΩ.
If the measured value exceeds 100mOhm, the line length and cross-section are queried to determine the limit value. For example, with an input of 1.5mm2 cross-section and 3m line length, the limit value is 300mΩ.