Except the reason people say decades is that's how long military procurement programs run for. Companies have order books past 2035 for many systems and standing up new programs takes time.
You start making yourself look unreliable now, then you prompt a transition away and by the time it's underway there's no reason to switch back anyway - i.e. traditionally stable companies "suddenly" are having trouble finding sales.
You start making yourself look unreliable now, then you prompt a transition away and by the time it's underway there's no reason to switch back anyway - i.e. traditionally stable companies "suddenly" are having trouble finding sales.