According to this datasheet, Semtech LoRa can reach 9375 kbps, while CC1125 from TI has a maximum datarate of only 200 kbps, despite both operating on the same frequency (868/915). To reach its highest datarate, LoRa must be used with it's lowest spreading factor, and CC1125 uses narrowband transmission, so the it seems to me that the difference in datarate should not be so great, and especially that it should be higher for CC1125.
What are the key factors I should look into to better understand what datarates are possible for sub-1GHz systems, and thus better evaluate the available systems (bandwidth/spreading/modulation/protocol/etc)?