Yes, it seems you are correct. For example this one is 180g including batteries: https://www.1001hifi.info/2025/01/sony-wm-20-1983-worlds-sma...

Though I stand by my implied argument that older devices were not as heavy as we might remember them to be. And it is okay to consider 240g a bit too heavy in the context of a digital music player with no need for cassettes or mechanical parts.

I read the advert as claiming that the headphones for that Walkman are 1.4oz, which seems plausible (they're a very flimsy design).