Definitely some recency bias in here.

And nostalgia bias

I haven’t even watched the show, but you can’t convince me the OP for Hunter X Hunter isn’t in the top five, yet alone the top 20.

I find yhe lack of cowboy bebop on that list concerning

There seems to be recency bias, and classic anime , and Ghibli OPs over quality.

I'll take Kiseki No Umi/Record Of Lodoss War OP

and

Heavenly Blue/Aldnoah.Zero OP1

and

Majokko Megu-chan

or any of those OPs by Creepy Nuts: Call Of The Night, Mashle, Dan Da Dan

Definitely missing the theme of the Gunsmith Cats OVA by Peter Erskine!

This list looks like:

1: The song most people probably recognized even if they didn't watch Evangelion

2-16: Either a recent anime song, or a "classic" anime song regardless of merit of the actual music (ie, we would literally be killed if we didn't include this, even if the song isn't musically that good)

17-20: Ghibli

Agreed. Also, no Mawatari Matsuko for all the Yuyu Hakusho songs. And even with recency bias, "il vento d'oro" (Jojo's Bizarre Adventure) by Yugo Kanno should also be there.

Nothing by FLOW?

slander

I'd have picked "Blue" (the final ED) rather than "Tank!", but at that point it's just a matter of taste.

Let's see here—of the songs on the list, I remember four, although I must have heard three of the others at least once. There's not just recency bias, but most-popular-series bias. Of course, if someone asked me to make a similar list, most of it would be stuff hardly anyone else remembers.