I'll take environmentally responsible planned obsolescence over the current situation.

Nothing lasts. Durable plastic and metal goods become damaged or worn. What then? When repair, reuse, or recycling is not socioeconomically attractive, having some sort of naturally sustainable cycle would be nice, wouldn't it?

Even if I have to buy a new phone case every seven months, if it's part of a sustainable cycle that becomes quite economical due to the massive scale -- wouldn't that be better than maintaining the current production of long-lived plastics?

This strikes me as an example of capitalism learning something from biology.