The most important part of lightning protection is grounding. Then comes grounding. And then comes grounding. Grounding however means: running a dedicated, large gauge (16mm² cross section and up) copper wire from the lightning protection to several grounding rods in the ground around your home. If you can't do this, forget about lightning protection altogether.
Why DC grounded antennas are no good for lightning protection, even though (mostly Chinese) manufacturers make that claim, is that they shunt the EM lightning energy away to the common ground, damaging or destroying everything that shares a connection to this ground. Your gateway for sure, maybe even your home appliances (through the earthing pin) or your router (thorough the ethernet cable). If they shunt altogether, because the DC grounding circuit is just a small resonant circuit that will never survive a lightning strike and possibly not even a nearby strike.
If you are unable to provide the large gauge dedicated grounding wire, then forget all about lightning protection. Any other measures will just give a false sense of safety.
But like @BoRRoZ says, you shouldn't lie awake from an unprotected LoRaWAN antenna either. In Europe you have on average 2 to 4 lightning strikes per km² per year. Most of them hit ground directly. The chance of one hitting your antenna is incredibly low, especially if there are other structures in the vicinity.
A completely off-grid gateway is the best lightning protection there is. Putting other poles in the vicinity and connecting them to other metal structures is a very bad idea and will negate the lightning safety of your off-grid solution. You should actually even increase the insulation between your gateway and your building, e.g. by putting it on a rubber mat. This will make your gateway 'invisible' for lightning.
In general, it is always a bad idea to put lightning rods in the vicinity of antennas. The near field effect will negatively affect the performance of the antenna.