The carb issue may or may not be due to the manufacturer,; many modern carbs are over-simplified and do not react well to the ethanol blended gasoline in use today. I very well remember the days of gasahol back in the 70’s, family truckster broke down regularly.
A lot of the problems are emissions related also.
You can do emissions pretty well with a computer controlled EFI/catalyst setup but doing them on low price carbureted outdoor power equipment is tough.
Some of the adjustments on the carbs are covered up with plastic or even pressed in brass plugs and it takes special bits to turn the screws once you do get to them.
My new Echo chain saw and string trimmer did not run well until I went on YT and learned the “secrets” of carb adjustment. You can buy the special adjuster bits on the internet for cheap.