Yes, new clothes almost always smell unpleasant, but the smell usually goes away when i wash them. (Although, i have a newish washing machine that doesn’t remove anything, it just sloshes dirt around. I should probably start a pit thread, if i haven’t already…)
If things smell different to you “since the covid lockdown”, it’s almost certainly you that has changed, not the rest of the world. Probably you had covid and it damaged your sense of smell.
I haven’t noticed “chemical” smell of new clothes, though the great majority of the ones I acquire these days are jeans-type pants, t-shirts and the occasional sweatshirt.
The most noteworthy stink I’ve encountered in recent times was that of a batch of black plastic plant pots, which had an industrial reek so strong I had to leave them outside for months to air out.
A lot of the dyes used in clothing and pretty much everything else are petroleum based so maybe that’s what you’re smelling… have you recently stopped smoking? I noticed that after I stopped smoking, that smells were more vibrant than before.