I mean, say, you want a really nice camera, or a drone, or maybe a gaming laptop, and since those things are made in China, they are too expensive to buy right now in the US, since tariffs are over 100%. So you just go to Canada, buy the thing, unpack it from the packaging, and pretend like its just personal items. Just like a smartphone.
AFIAK, border agents usually don’t ask if you bought your phone in the US or from outside, they shouldn’t ask about other personal electronics, right?
You can! But you can’t buy many of the same item (otherwise the law assumes that you’re buying with the intent to sell), and you’re likely to spend more money traveling there than you would just buying normally with the tariffs and everything. Unless it’s a specially expensive item, I doubt it would be worth it.