While the claim of selection bias in JetBrains' survey may be argued, it is still a valid data source, which is what the gp was asking for.

Also, your anecdotal data is arguably biased as well.

My take is that many sources, including the ones linked to in the tweet's replies point to solid growth in Python 3 adoption. Python3 might not have overtaken Python 2 overall, but it's very far from being "dead".