Data point: trustworthy Chinese eBay vendor

[Analog Kid]

I recently received some chips I ordered from an eBay seller from China. I eagerly awaited their arrival with the hope that the chips weren't fakes. (I ordered 5 74HC4067N MUX chips for a potential inverter project. The total cost was less than $8, much much better than anything else I could find online.)

Well, they came, I tested them and they work. So I thought I'd note this seller to anyone who is looking for relatively inexpensive NOS chips and such. The seller is "ICInventory".

Of course, this only one instance, but judging from both their feedback and from the communications sent between us, I feel this outfit can be trusted.

[wraper]

Judging from photos this seller sells salvaged e-waste as brand new parts, example: https://www.ebay.com/itm/276393035859
IME nearly all Chinese sellers sell mix of counterfeits and genuine stuff. Something working on a first glance does not mean it's good and genuine.
Overall I suggest buying SMD parts from reputable place instead, 74HC4067N is obsolete, so chances of getting genuine brand new ICs are slim, but you could easily buy genuine ICs in SMD package cheaply at say LCSC.

Of course, this only one instance, but judging from both their feedback and from the communications sent between us, I feel this outfit can be trusted.

Means nothing, you'd see significant percentage of negative feedblack only if seller blatantly scams people with f-off attitude when caught by more knowledgeable buyers. And actually seller has some negative feedback about counterfeits.

[Analog Kid]

Well, as always, caution is advised. Maybe I just got lucky and got the "stopped clock" good parts that day ...

[Haenk]

This might work the other way round, too.
Purchased a couple of parts declared as "desoldered" - instead received new (original) parts instead.
(I did intentionally buy desoldered parts, as they were uncommon, and too cheap to fake them for a profit, even for chinese standards, only 10% of them being "good" would have been a good purchase...)
But in general, I agree, you often don't what is pictured or described...