What will likely be the last decade Gen Z will consider "old" when they're older?

Like every generation, once a majority of them are mature adults or middle-aged, they'll see newer decades as "modern" and then decades where they grew up as "old." Gen X perceives the 2000s as relatively modern, whereas Gen Z views them as retro. But, what do you think will be the last decade most of Gen Z will consider to be "old" by the time most of the time are mature adults?

2010s
2020s
2030s
2040s
Other
Select gender and age to cast your vote:
What will likely be the last decade Gen Z will consider "old" when they're older?
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