One of the oddities of Traveller economics is the existence of imperial goods from TLs other than 15!
Hardly, given that many subsectors lack a TL 15 world. Local TL 12+, sure, but a great many things currently don't qualify as TL 8 goods... T-shirts are introduced in TL5, and mature in TL6 - the only change of note is the use of poly blends - and that's TL 6. The TL 9 US and Europe mostly just buy ones mass produced in the TL 6 and 7 second world nations.
Likewise, the AR-15 and AK-47 are both TL 6 weapons; the vast majority of those still being made are being made to TL-6 standards.... but the Afghanis were making AK-47's with TL3 tools from TL4-quality sheet stock and wood. Not as good a performance, due to poor tolerances, but serviceable. And they're arguably the two most used rifles in the world.
Most people are still using TL2 products on a daily basis... paper, pencils, forks, spoons, knives, glassware.
So, no, it's not an oddity. When the lower tech version is good enough, the higher tech never takes over, at least until the methods of production make it cheaper to automate than pay craftspersons.
And yes, while most paper is made in first world nations, on TL 6 or 7 machines, the paper being made is of comparable quality to that used in China some 1600+ years ago... a starchy pulp slurry collected on a fabric screen and drained, then allowed to dry. The automated system merely produces much more consistent result at much higher rate, but fine writing paper is still made the traditional ways in the US, UK, & Japan. The paper itself is, usually, not dissimilar to hand made fine papers with the correct skilled craftsperson.