Working as a data scientist, I have exclusively used Altair since I joined my company in 2021. Every one of my coworkers uses Matplotlib. Two people said something like "Oh, you're using that library that's supposed to be better and probably is, but I just don't want to relearn everything for plotting" but nobody else has even shown interest, let alone taken the plunge.

If you need to learn a plotting library and you already work in Pandas, I recommend choosing Altair to learn. It's a natural extension to pd.DataFrame and the only magical incantation to learn is

    alt.Chart(df).mark_<plot_type>.encode(x=df["col"], y=df["other_col"])

I find this significantly easier to work with than Matplotlib, where the same things can be done in several ways with subplots, plt.figure(), df.plot(), and maybe others?

My only complaint with the library is that outputting to an image file feels weirdly complicated. I often resort to making HTML files and taking a screenshot if I don't want to take the time to look up all the steps equivalent to `.savefig("file.png")`.