True to some degree, but since you are comparing oranges and apples,
it's not that easy to answer.

But gliders tend to fly in good weather only, and the number one cause
of accidents in GA airplanes is flying VFR in IMC conditions.
Running out of fuel comes fairly often too , which you won't see in
gliders obviously.

Are gliders safer?
Perhaps, but I take them just as seriously as when I am flying a jet,
for example....

Richard
ASW19
Phoenix, AZ