They are, or were, extremely trendy among the tech workers of the Silicon Valley / San Francisco. They're premium priced and definitely casual in style and fun

They are, or were, extremely trendy among the tech workers of the Silicon Valley / San Francisco. They're premium priced and definitely casual in style and function, with a sustainability-focused marketing sheen. I've had a few pairs and the quality is above-average but definitely not a "buy it for life."