LoRa is not an open physical layer protocol standard, but rather an interesting niche chip product from a small manufacturer.

Like all unicorn chip products, setting up a link in SDR is not officially supported without violating IP rights. =3

LoRa has different frequency bands in different parts of the world. Getting boards that work well across all bands is all but impossible - EU is 868 MHz, US/CA is 910 MHz, AUNZ is 915 MHz. Either you make different versions of the boards with filter stages tuned for the region-specific bands, or you use next to no filtering at all which means you'll end up with the RX stage getting saturated by nearby stations (especially phone networks). The third idea is to use RF switches with different filter networks attached, but that's adding a lot of complexity and BOM and you got to deal with insertion losses on not just the filters but also the switches, and filters that can deal with higher output powers than 22 dBm can get pricey.

Oh and then you got the question of the bandwidth of the filter. Ideally you want as low of a bandwidth as possible (e.g. Meshcore is 62.5 kHz, Meshtastic 250 kHz), but the SRD band in which you can legally run LoRa in Europe is 821-870 MHz... yeah good luck, you can't really do that, you need hardware for any serious usable filter that doesn't get stuffed over by nearby disruptors.

The antenna question is a different thing. That one is easier to solve as you can just ship different antennas tuned to different bands to different country SKUs, but it is nonetheless a pain to deal with.

Edit: Oh and I forgot, LoRa is proprietary IP from Semtech. There's lorarx written by some hams that can work on your average rtl-sdr... but as the name says, it's receive only, I'm not aware of anyone doing SDR transmission for Lora.