Maybe the fact that modern Briggs engines have plastic cam lobes and timing gears that are prone to failing might have something to do with this? For a comparison harbor freight predator engines have metal cams and while the timing gear is still plastic its more solid than the Briggs one.
I have a Harbor Freight little Tailgator generator I use a lot at a location with no power.
To run a power tool or a fan, it’s great.
That little unit will pump it’s heart out.
I typically run a couple of tanks of mixed through it on a day on location.