These days, radio is still a powerful tool but it's often underappreciated. Whilst one can have the TV on it's not of much help unless one's watching it, whereas radio is more intimate in that one can go about one's daily life and its presence is still with one.
What you observed about your mom's life I've also seen in my own relatives especially the women in my family whose partner had died. For them, the radio was pretty much a 24/7 comfort and a protection against loneliness. My appreciation of this never fully struck me until they'd died. It's now a big regret that I never spent more time with them when they were alive. The fact that I cannot undo that hurts.
(BTW, I often post comments on line more as a diary or aide-mémoire to remind myself of what I thought about a story. I wouldn't bother to do so if it remained on my home PC but the added incentive that others may read it spurs me to write. These days, there's so much competition for people's attention online that one posts on the understanding that if one's lucky one's comment will receive a few fleeting glances. Occasionally, when one receives genuine heartfelt feedback as with your post, it makes one's efforts feel as if they've been worthwhile. Thanks.)