The triangulation method needs some astronomical azimuths to be observed at 200 km-300 km from the fundamental station of the geodetic network and one or two baselines to be observed. With these observations, the angular and the scale quality of the network will be verified so that the surveying accuracy is obtained.

What 'scale' is the surveying you mention occurring? Some context would be helpful ( like garden beds lines in an urban Pea Patch, up to historical continental like the US Mason-Dixon line: https://www.asce.org/about-civil-engineering/history-and-heritage/historic-landmarks/mason-dixon-line ). The context also provides the collection of devices and tools used, all work together and affect the precision and accuracy - rarely is just a single one used. Also, the various surveyor's chains and steel tapes ( https://allterracentral.com/keson-snr-series-300-ft-nylon-coated-steel-tape-with-dead-foot-and-ring-units-1-10-1-100.html ) are much different than the conventional 'tape measure' ( https://allterracentral.com/keson-short-tape-measure-with-nylon-coated-ultra-bright-steel-blade-1-inch-by-33-foot.html ) you mention. Whatever the instrument used, however crude, it is the methods and techniques used that most influence the precision and accuracy, for instance massively repeating the measurements by multiple people under different conditions and and analyzing the cumulative results can achieve far greater results that one would expect from even very crude tools - the tools don't 'cause inaccuracies', any eventual errors are the result of process.

Not provide accurate results compared to what?