Anything you can buy from HF is questionable.
In fact, if you get your project done with it and you get more out of it great.
Got a cheap drop light, work great for awhile, then would be intermitant.  Finally got fed up, took it completely apart, found a bad solder joint repaired it and now it works great again.

labor conditions over there are terrible, worst than sweat shop.

been using one for a year without any issues

I have a Big Lots & a Harbor Freight 4&1/2" . Had em for around 3 years I guess. The Big Lots was a B&D product, with a slide switch. I use it as a grinder. The HF is a cheaper one, with a pale switch, it flexed & stopped pushing the Go Button far enugh to make it run, even with he paddle fuly pressed down. Opened it up, bent some wire, epoxied it in & it works fine now, but I had to butcher the case a bit, to make room for the wire & epoxy.
HF abrasives are lousy, buy Norton or something from a Big Box store.

IDK hoot about the die grinders. If its trash, trade it back to them, youll either decide they all suck or just some of them suk.

I've never had any problems with there tools.

I bought their 4 1/2" angle grinder which I think has the same motor.  Someone on here, probably JOG, advised us to pop open the gearbox and put some real grease in it.  I did that, and the grinder has not disappointed me at all.  It's done the job I bought it for, then several others, and keeps on chugging.  When the motor fails, I'll try the replacement brushes, which where included in the $15 sale price