I think a big reason Hubble managed to do that was that it captures in the visible spectrum due to being a repurposed spy satellite. That spectrum just isn't that interesting these days afaict, especially since ground based observatories have gotten a lot better at seeing through the earth's atmosphere. The false color images of most of today's missions are just a lot harder for the public to understand. It was also launched in a time where NASA desperately needed good publicity.

In the late 1990s you'd walk into Walden Books or the equivalent store and this would be staring at you:

https://i.imgur.com/Go5VDi1.jpg

And it seemed truly astounding. Like we were getting to journey across the universe. The visuals that Hubble presented, the variety and scale of that style of imagery (great for PR), and the way it cultivated the imagination of the mass public, is still unrivaled.

Because it must be American to catch attention in American media.

Hershel took awesome images. For example:

Galactic outflow with the Suzaku X-ray astronomy satellite https://www.esa.int/var/esa/storage/images/esa_multimedia/im...

Herschel’s view of new stars and molecular clouds https://www.esa.int/var/esa/storage/images/esa_multimedia/im...

The Little Fox and the Giant Stars https://www.esa.int/var/esa/storage/images/esa_multimedia/im...

Star formation on filaments in RCW106 https://www.esa.int/var/esa/storage/images/esa_multimedia/im...

Feathery filaments in Mon R2 https://www.esa.int/var/esa/storage/images/esa_multimedia/im...

Herschel was more modest in size, 3.5 meters vs JWST:s 6.5 meters. Also ESA PR is not as great as NASA. NASA is the gold standard in this regard.