YouTube makes it easy to follow the change in the anime world over the decades. Anisong is sufficiently popular that several users make playlists or clip videos showing plenty of them along a theme. This one? Gundam openings, starting a PS2 remake of one of the original series' openigns and ending with Iron-Blooded Orphans.
You can see in these openings theme sequences all of the tells that JD Cowen and others have talked about previously about how the business went wrong since the late 1990s. You can also see in similar playlists how the 70s Super Robot scene went stale as the years progressed, allowing the original series to break out despite its first run being less than successful.
It's not just the animation techniques and quality. You can see in the music and lyrics the same tells of a healthy or ailing culture at the time of production. What you see here in the opening does give you a sense of what the show proper is like; for those skilled in composition of artwork, you can glean vital information just by watching the openings.
The first impression you get from the opening is often the correct one, with the times you go wrong often the result of deliberate concealment or subversion of audience expectations. Go take a stroll around Anime YouTube, focusing on openings and endings, and you'll find the patterns that let you see at a glance what we've been talking about the last couple of days.
And yes, this is not confined to the mecha shows.
So when you're going about making your contributions to #AGundamForUs, don't be shy about making a playlist of show themes, sequences, etc. that have the vibe you want. For example, I'm clearly taking this as inspiration:
In addition, of course, to this:
And plenty of non-anime influences. The ingredient list is not a short one.