Gold
666
Breakdowns are a break in the rhythm, but aren't' necessarily a "groove". You can't just slash groove and rhythm together. Pretty much all metal (and music in general for that matter) has rhythm, but not necessarily "groove".
Besides, the "groove" we are talking about here isn't just a rhythm or something. It's a particular style of riff and/or beat that gets used in some metal and metal adjacent genres. One that was heavily abused by nu-metal, and has effectively tainted my ability to enjoy it.
all breakdowns have a certain groove to them, i'd love to hear one that doesnt