Use of 865-868MHz band & power density in EU

Hi,

I am designing my own LoRa protocol with specific frequency channels for EU ETSI compliance. I did some research and saw that the band 865-868MHz is almost not used at all and I wonder why it is so? See this report on page 34: https://pdfs.semanticscholar.org/7ff6/bbe6ceb4cb984a11fa7a251a5ce961cec124.pdf?_ga=2.119372608.879315852.1561666454-382131801.156166645.

ETSI states a Power density for that band:
" -4,5 dBm/100 kHz The power density can be increased to +6,2 dBm/100 kHz if the band of operation is limited to 865 MHz to 868 MHz. "

But I am not sure what the above requirement means and if this is a problem for LoRa messages at 125kHz bandwidth with 14dBm Tx power?

Thanks in advance!

Thibault