I’m over 50 & I wear them. It’s a nice look. I think the big t shirts / shirts look better with shorts than leggings.I like the look of oversized tshirts and cycling shorts, but even though I wear leggings I'm nervous to wear cycling shorts or any shorts. I'm also 42 so not sure if I'm too old for them.
But a cheap pair of shorts & wear them round the house and then to Sainsburys etc. you’ll soon realise that no one really cares. And I bet you’ll look great.