Back in the old days (Phantom 1), it was all IP. The "range extender" box that you could buy for the controller was literally a MIPS box running OpenWRT. I took one apart and used a debug interface to jailbreak it, then connected my own RPi to its network and used it for some degree of autonomous control. I assume things have advanced substantially since then.
I was very disappointed that my Mavic Mini 1 could not be controlled through the DJI SDK so I couldn't use any external apps to drive it. I assume that has also improved, but for a minute at least, the cheaper DJI drones were essentially unusable for my use cases.
To some extent, the availability of cheap commercial gimbal camera drones really set the OSS side of the hobby back. Eventually most of that energy moved to FPV acro drones, but definitely something was lost, as nobody really tries to build a DIY DJI competitor anymore. Of course, DJI drones are absurdly performance limited compared to what is possible with similar sized platforms.
I was very disappointed that my Mavic Mini 1 could not be controlled through the DJI SDK so I couldn't use any external apps to drive it. I assume that has also improved, but for a minute at least, the cheaper DJI drones were essentially unusable for my use cases.
To some extent, the availability of cheap commercial gimbal camera drones really set the OSS side of the hobby back. Eventually most of that energy moved to FPV acro drones, but definitely something was lost, as nobody really tries to build a DIY DJI competitor anymore. Of course, DJI drones are absurdly performance limited compared to what is possible with similar sized platforms.