In my experience that isn't close to true. FYI, you'll need a really smokin' drummer who truly overstands (sic) the style to come close to pulling it off convincingly. I've played with guys who are pros (literally) that can pass it off well enough but there's a huge difference when a guy steps in that can do it right.
Check out some reggae bands live sometimes ... the rare times any play here. You'll see that everyone keeps quite busy. There's the appearance of a trance to the casual listener or dancer, but there's much more going on.
As I'd said to you, I love the challenge of keeping the one big groove - if any instrument keeps it steady in that style throughout a tune it's usually the bass - but while that might seem easy on the surface it's actually quite a challenge and IME tougher than playing stuff with a lot of changes and leeway where you can hide and make flubs.