IR is fine for these things, it's not like they need much data. I have an IR ceiling fan, no issues there (even if the receiver is on a little wire that is supposed to stick to something but the sticktivity of the tape sucked), and a radio "smart" lighting system (just simple on / off switch on a plug socket). And some radio spots from IKEA, although I'm sure that can be hooked up to a "smart" system.
IKEA has consistent smart system that has the annoying feature that it works the wrong-way around for my use-case. The cheap IKEA switches can control IKEA peripherals only directly, you can't use them to control something outside of the IKEA ecosystem. As most of the things I want to control are either HomeKit native things or digital outputs on PLCs it does not work for me. So in the spirit of true overkill I have few switches that contain OrangePi Nano (I had somehow absurd quantity of these laying around as leftover from previous even more misguided project)
You should be able to integrate your IKEA and Homekit devices into the one if you use HomeAssistant.
The IKEA Tradfri system is all Zigbee based - I have a bunch of their light bulbs and strips, plus a few smart power plugs. I personally have them attached to my own Zigbee controller, but there's also a Home Assistant Tradfri integration if you want to keep using their Smart Hub controller.
There's also a Home Assistant homekit integration, so you can use HA to orchestrate events happening on the Tradfri side to trigger something in the Homekit side, or vice versa.
(I don't have the Tradfri smart hub or Homekit devices, so YMMV on specific possible options)
My beef is with the fact that the battery powered switch wants to be paired with the thing it directly controls and cannot be used alone with it just controlling something that is on the other side of the tradfri gateway. The five button round one apparently can be used for that, but the two position square one can't.
By the way the tradfri gateway is weird piece of hardware, the thing is mostly empty and only contains small board with apparently the same RFSoC as all the other tradfri peripherals connected somehow to ethernet PHY…
