Before responding, first let me say
thank you for all the work you have done and continue to do. Also as I wrote above, I view Julia as superior to Python in every other way. :-)
By "ecosystem" I mean much more. PyPi currently offers around a quarter million Python packages, versus thousands for Julia. Github code and activity using Python is also currently around three orders of magnitude greater than for Julia. Python is currently the fourth most popular language on Stack Overflow (after JS, HTML, and SQL). It's a gigantic ecosystem that has evolved over three decades.