What happened to the 3CCD camcorders? Back in the day they were everywhere [There was even a handheld Panasonic one!] but today they dont exist at all?

I can't find any 3CCD camcorders with SD card video recording because I don't want to fiddle with Mini DV

What happened? Are there any Full HD or 4k 3CCD camcorders these days?

Looks like the ugly CMOS replaced them...
"The ugly CMOS replaced CCD" because of cost, complexity, power consumption, pixel density, light sensitivity, etc. In every regard — except of the rolling shutter artefacts, of course — CMOS sensors are better. They also do not exhibit the saturation trail effect, the vertical "ray of light" that occurs when pointing a CCD camera towards very bright light source.

You can find a 10-year old tapeless 3CCD-based camcorder on eBay for less than $100. For example, Panasonic HDC-SD5 or HDC-SD9, the latter records progressive HD at 24 fps. Better than Super8 ;-)