It would be awesome being able to :

• compare years between each of them (1)
• compare stats with the highest value (2)

Basicaly for each "block" or stat you could toggle two small buttons that show up on hover.
- Compare with highest value (2)
- Compare with previous year (or a specific year but I know it's not an easy task to display a dropdown in such a page (that's why you haven't found a way to allow us to select a year range for Year in Review feature yet)) (1)

for TV shows or people ranking, you could also display :
- the ranking that show had in that other year (1)
- the highest it's ever been in a single year (2)

All these informations could be enhanced with with numbers (like +20% , +5hours, -2ranks)

so for example I could see
- week 33 I had only 9 plays but in 2016 I had 36 plays (2016, +27 plays(or +300%))
- week 44 I had 27 plays and in 2016 I had only 9 plays (2016, -18 plays(or -200%))
- Big bang theory was my most viewed TV show in 2018 but not this year (2019, -5 ranks)

Not sure how to do this with the movie/TV show networks.

On ALL TIME stats I would also suggest this but only for option 2. Being able to see how much each highest value brings to the total
Something like 2000 plays between 2015 and 2019 but my higest year was 2016 with 500 plays (2016, 25%)

I'm sure this needs more analysis and more thinking so I'm just giving a little suggestion :-)