A TI-84 Plus calculator (over 20 years old) is still useful today.
In isolation, I don't think a model necessarily becomes less useful over time. It'll still be as good at summarizing articles, translating text, correcting grammar, etc. for you as it is today.
If things do continue to advance and new models are released, which I think is likely, the old ones become less useful by comparison and in situations where there's competition. But then, through hardware/algorithmic improvements, better models also become feasible for universities/open-source groups/individuals - so you shouldn't be stuck with a 2024 era model.
In isolation, I don't think a model necessarily becomes less useful over time. It'll still be as good at summarizing articles, translating text, correcting grammar, etc. for you as it is today.
If things do continue to advance and new models are released, which I think is likely, the old ones become less useful by comparison and in situations where there's competition. But then, through hardware/algorithmic improvements, better models also become feasible for universities/open-source groups/individuals - so you shouldn't be stuck with a 2024 era model.