It's because they're off-lease trash that they hobble back together with used HDDs and used RAM. They target low-income; budget conscious/frugal; elderly and those otherwise ignorant of the scam. Backed by a 30-day return policy!

I get these types of machines (actually somewhat newer i5/i7 11th gen+) from an Amazon returns auction house for $5-$20/ea and they invariably have mismatched ram in them and HDDs with 50-70K hours on them already. They also typically won't boot because of a faulty ram stick 9r failed HDD.

That being said, I also have 4 kids and those machines have served well as 'starter' systems. They get to upgrade the PSU, HDD-->SSD, GPU and max out the ram on a shoestring budget.

Between a local MicroCtr and /r/homelabsales ... They get to build out performant systems for $300-$600 total. I also consider this to be a much greater investment than just throwing a console at them.

Profits or not for them; we found some profit in their waste stream.