It is complicated. For very popular artists yes, their music is commercially short-lived and most of the returns will come in the first six months. But for the more obscure composers and performers the reality is completely different.
It needs to be something like 12 + 12 or 20 + 20, or even 20 + infinitely continuable for a gradually increasing cost. It still has the potential issue of waiting out that 24 to 40 years; but companies are less likely to do that, when a few years is basically nothing.
It's been 2 years since covid started, for example.
The more effective approach would be to simply remove the economy entirely. In a post-scarcity or communist or whatever you want to call it society, you could abolish copyright entirely without hurting anyone, because no one's able to profit off it in the first place and spending effort on things that don't pay off is no longer penalized.