1. Magic Keyboard has a pass through USB-C port on its hinge for charging iPad Pro and iPad Air (4th generation 10.9”), freeing up the port on the iPad for other accessories - we can use the USB-C port on the iPad to connect headphones. At $299 ($349 for 12.9” iPad Pro), Magic Keyboard is expensive but we can expect the quality, durability, reliability and functionality of Apple products from it - and currently, this can be the best available option -
https://www.apple.com/shop/product/M...ion-us-english
2. MagSafe - if Apple brings the $39 MagSafe charger to iPads (I expect the next generation of iPads will support MagSafe), it will free up the USB-C port for headphones -
https://www.apple.com/shop/product/M...agsafe-charger
3. Gen2 USB hub. Gen2 connects the headphones to iPad even if you plug in the power after the battery is discharged. Gen2 still has issues of low volume (about 65% volume) at max setting and also remote buttons of EarPods don’t work but we can live with them and they may release a firmware update to resolve it. I’ve already informed them of the issues and they said they would send it to their team.

https://www.hypershop.com/collection...gen2-usb-c-hub
NOTE: Do not buy their HyperDrive as it has too HIGH volume issue at the lowest setting and also it does not connect the headphones on plugging in the power if the iPad battery is discharged (you need to plug/charge iPad through HyperDrive before the battery dies so you can use the headphones or unplug and replug the power losing a charge cycle of the battery). They confirmed they cannot fix the high volume issue as it was manufactured by another factory. It is also a hassle plugging cords/drives in and out while the HyperDrive hub is plugged into the iPad - you need to securely hold the hub while doing so. Its portability was just hype when it is attached to the port so weakly that can pull out at the slightest movement. Gen2 on the other hand has the cord plugged into the port while the hub sits on the desk - providing some snug safety at the cost of portability. Do not buy any hubs that plug into the port directly because the port does not offer a tight hold.
Also note, both Gen2 and HyperDrive don’t work with Apple EarPods' remote buttons!
CAUTION: Just remember that the design of USB-C is flimsy (most probably the reason why it did not make into the mobile iPhone) and not as rugged as the Lightning - you should always be conscious about how/where the cord is dangling, be very careful while moving the iPad if it is plugged in and probably should tuck one end of the cord under the device to restrain its movement just in case you snap it unexpectedly, it will safely stop from damaging the port.