From what I can tell, they mostly live in video cards at this point.

There used to be an elgator capture card with some encoding, i _think_/

El Gato has one, it's really nice: https://www.elgato.com/us/en/p/game-capture-4k60-pro

That is a capture card and not an encoder card. It does not feature any accelerated encoding and relies on the host system to provide the video encoding, usually via a dedicated or integrated GPU.

It also costs like five times the price of the Pi itself.

I got a metal box with HDMI and an ethernet ports which encodes the HDMI video + audio and serves/publishes H.264 RTMP/TS segments. My intended use case was actually working with Pi's on live streams, installing fresh systems and the like where encoding might not be available anyway.

I couldn't find the one online but it looks like there are a few out there. Side note/tangent, the Pi3 was powerful enough to transcode 720p down to lower resolutions in real time.

The quite popular Logitech C920 webcam used to natively support H.264, but they dropped it in a model revision a while ago, because "nearly every computer offered in the market features a chipset that can efficiently encode high definition video at 1080p" [1].

I've used that very camera (without the accelerator) on an RPi 4 myself, and the only way to get acceptable quality was by using the Pi's H.264 hardware encoder.

[1] https://www.logitech.com/en-us/video-collaboration/resources...