This may sound stupid and petty/personal given the very large scope and seriousness of this, but whoo boy when I first saw this news a couple of days ago, I finally jumped on buying new sticks and button pads for my Steam Deck.
I've been using it a lot, and the sticks were drifting, buttons/dpad got mushy... so yeah, pulled the trigger on getting replacement/upgrade parts (hall effect sticks with more resistance, 'clicky' button boards and replacement gel pads) that are only made in China, arrived a couple days ago.
If the de minimus exception is fully going away, I think the import tariff/shipping fees on these would... be more than the ~$50 cost of the actual things.
But anyway... yeah, this is uh... very, very bad for everyone in the US who is used to buying ... anything not made in the US... which is basically everything.
Back to Great Depression style re-use/repair everything, or die broke and starving.
Online stores like Amazon, other large e-tailers like Walmart... they're still gonna have some stock left in their domestic warehouses... but that won't last probably more than about a month, depending on the kind of product.