Since when? Dortmund are 5th... closer in points to 10th than 1st.
Since 15/16 Bundesliga have had 7 teams reach the KO stages of CL. Their current respective league positions are 1, 2, 3, 5, 6, 8, 18
That's ~40% of the whole league.
Perspective, same time span:
England 6: 1, 2, 3, 6, 7, 9 30%
Italy 5: 3, 4, 5, 6, 7 25%
Spain 5: 1, 2, 3, 4, 14 25%
France 3: 1, 3, 4 15%
0.13 more goals are scored each Bundesliga match compared to the rest of top 5. Basically a marginal difference.
I don't know where people get the idea from that it is a weak league, but it's clearly not based on facts. A recent pattern of former Bundesliga players dipping in form upon joining PL sides is probably a factor, but for every Havertz/Werner/Haller there's a De Bruyne/Son/Sane.
Haaland's numbers are ridiculously good for a 20 y/o, it's a shame if people downplay him over myths and false narratives.