When Dortmund was consistently second in the Bundesliga, I remember comparing the budgets of the clubs and Bayern's was twice as high, that is, even at the level of first and second place there was no real competition. I doubt that anything has changed since then.
It's always hard to guess what the new season will bring. Relying on player statistics alone cannot be accurate. Indeed, when viewed in the league Munich is always dominant and wins more leagues. But I don't think that will absolutely continue. Matches will always be unpredictable and there will definitely be many surprises. I don't think Kompany will think the league is an easy competition either, if they underestimate I think it's a bad problem for them. The league will start soon and I will be happy to see the Bundesliga matches. Munich will kick off the league on August 22, against RB Leipzig.
You can assume/hope for a lot, but there must be some basis for this if you want to argue with bookmakers (who are responsible for their assumptions with money). In sports it is impossible to accurately predict the outcome (or rather to determine the probability distribution of possible outcomes), but bookmakers are considered to do this with satisfactory accuracy, so Bayern's dominance can be considered a reasonable assumption.