There are not that many farmers, though, and tractors are relatively slow. If you consider that, the impact of those protests was quite high.
You're assuming "with a tractor" was the only way for farmers to show up to these protests. It was not; many of them showed up in plain cars.
> impact of those protests was quite high
Indeed, mostly because they were very disruptive. Despite prior assurances, they even hindered emergency services in performing their jobs.