Of top tier/high prestige competition, including both club and international football, which tournament has the fairest refereeing throughout the years? The UCL? World Cup? Euros? One of the top domestic European leagues? Factors include quality of referees and decisions, good VAR usage, least corruption etc.
A myth can be true. I watch a lot of Bundesliga, but rarely other big domestic leauges to compare. Compared to national teams, CL, EL, Conference Leauge and lesser domestic leauges, however, my opinion is that Bundesliga has very good refereeing (and VAR usage).
An important reason is some of the referees ability to speak to the players and understanding the game.
That said, it’s not black and white. There are both good and not so good referees in the Bundesliga.