Its hard to say without knowing the kid.
My teen DS HATES anything 'trendy' or 'fashionable', he rolled his eyes so hard at the prime craze etc... so most these suggestions would be wasted on him.
I actually don't know ANY teens in real life that are into the so called 'big trends' you see mentioned online (not to say none are obviously so kids love them).
There a lot of 'Alt' kids at DS school that are now big into 'older' (hurts to say that) bands, like My chemical romance, Nirvana, Iron maiden, Metallica (which was made big by Stranger Things so getting more mainstream).
Plus then theres all the kids that love 'nerdy' fandoms. I'm not really knowledgeable on that but my friends kids get really into fandoms and collect loads of Pop figures and fan specific stuff etc... some recent mainstream fandoms (although they might be over now) included stranger things and squid games etc...
My DS personally kind of likes silly thing to fidget with (plus anything 'gaming' related but thats obviously harder if you don't know if they have access to anything like that).
The things people always suggest for these never sound like gifts just necessities with branding on. as a teen if my Christmas present had been a hype school bag, nike socks and a lynx set I would probably be even sadder than getting nothing because its kind of a salt in the wound gift.
This is why buying blindly can be a nightmare.
If I had to guess I would maybe go for something more 'fun' like games (maybe exploding kittens), fidget toys (rubix cube type stuff), classic toys (2,5 & 15 all my kids love a ball), a hobby item (like an instrument they could learn and get good at) or maybe take a punt on whatever the big fandom is at the moment.
Instead of the cheap stereotype of Lynx (lets be honest no teen actually wants that) I would go for something like David Beckham which is also very affordable.