The new tablet system has immensely nerfed unique tablets.

The value of the delirium unique tablet was not the delirium it gave.
It was using the non dissipating fog with delirium from other tablets.

The value of the breach unique tablet was not the breaches it gave.
It was using the non-closing breaches with breaches from other tablets.

I could repeat that sentence pair for the other tablet types.

The point is, Clear Skies, Wraeclast Besieged, etc., these tablets are not supposed to work on a measly 10 maps.

They're supposed to work on 20. 30. 40.
Because you stacked them with matching regular tablets.

You could put two other Delirium tablets in the same tower as Clear Skies.
You would put other Delirium tablets in towers that overlapped.

I'm not sure I even care about unique tablets anymore.
They don't feel good when they affect such a small number of nodes.
Eliminating the ability to stack regular tablets on the unique tablets to use the unique affixes on the content added by the regular tablet does not strike me as a genuinely intended component of this update. It feels more like a major oversight.
The stacking was what gave the uniques any real value. What made them worth wanting.

Towers:

If we can't apply tablets to the world map over a range anymore, then surely either there should be some other way to use the unique tablets modifier additional times by taking uses from regular tablets, or just buff the usage amount of the unique tablet to the number of nodes we would have stacked to before.

Edited Addition:

Commenters here proposed an idea worth bringing to the original post.
+1 from me to it, it's an effective way to counteract this massive nerf to uniques, and make towers something that still have an actual reason to exist.

Their idea, was to make it so that towers still had a tablet slot that works the old way, to put the unique tablets in, while regular tablets are used the new way alongside the waystones.

On towers there should be a separate space for a single unique tablet. The player would get three normal tablets and on towers a separate space for a unique tablet. That is if they’re planning on keeping the atlas the way it is. It’s not great.

While not a perfect solution, I think it would be interesting if we could still put unique tablets in towers. That way we still get the effect over a large number of maps. It would also give importance back to towers so it doesn't need to be scrapped completely.

Lore wise it could just be said that the unique tablets are too powerful to apply to an individual map and must be placed in a precursor tower device.

Just an idea, but with some polish I think it could be a great change.

Beat me to typing out the idea. Glad to see I wasn't the only one thinking it.

Going through my tablets in my stash and I've noticed my copy of Wraeclast Besieged, the breach tablet to keep breaches open so you actually get to fight all the breach monsters, a tablet that to be absolutely clear I have not used, has only 5 uses.

5 uses. I get to use the unique tablet on 5 maps. Total.

If I had managed to get this tablet into a tower just a few days ago, I could have used it's affect on 30, 40 maps of breaches.
Now I get 5.

How could I possibly get myself to care even the slightest amount about this tablet existing if it only works on 5 maps.
I may as well disenchant it. Utter trash.

They should add another slot for unique tablets.

Unique tables should have at least 6 modifiers and 300% increased xp gain. This is a true unique tablet. Otherwise don't call it uniques.