I think the German league, or Bundesliga, is not just a farmer's league. The evidence is that other teams can become champions and compete fiercely against Bayern Munchen. For instance, this season, Bayer Leverkusen has been incredibly strong and capable of leading the standings with a 5-point difference from Bayern Munchen. This differs from the French Ligue 1, where PSG is highly dominant, both financially and in terms of squad quality, as well as consistently leaving their rivals far behind in the league table.
PSG has got a different kind of dominance in their domestic league such that they will enjoy this dominance for a very long time because it will take a long time for another team to come up financially to challenge PSG in their domestic league in next few seasons.