Ironically, the most unrelentingly boring and defensive style of soccer is to be on offense most of the game, by maintaining possession and doing nothing with it. I say "ironically" because teams that maintain possession and "build slowly" usually receive credit for aspiring to play beautiful attacking football. When it works, and the offense circulates the ball around in nimble interchanges until they pounce on an a…
It depends I'd say. Bayern played a lot like this in 2020, which also lead them winning the Champions League. The key difference to what you describe was that they circulated the ball waiting for a chance to play an extremely fast attacking leading to a goal. Like an explosion after a few rounds of slow passing.
Just look at their chapions league final goal. Or even look at their 2021 first match against PSG. Barcelona was in the strangulating business. Bayern was in the smashing things open business.