I think this old kind of minifig packs of the 80s were much more effective than the currently available ones.
1 pack = 6 minifigs + 1 or 2 accessories each
It's not that complicated, could cost today certainly less than 10$/e.
Now we have impulse sets of 3$/e with 1 minifig + 2-3 accessories and a bunch of tiny bricks. It's not bad, but somehow not cost-effective IMO, and despite the large number of impulse sets, you still have very little choice within a theme. Buying multiples gives you identical minifigs and too many spare bricks and accessories IMO.
The new pack of 4 city figures is a good idea, it meets my favour much more than the impulse sets. It still has less minifigs and more bricks than the old packs, but roadsigns, park benches and semaphores seem to be much more useful in multiple copies compared to the typical content of the impulse sets.
Same should be done with all other themes: pirates, castle, space, star wars, indiana jones, powerminers, ALL of them should get 1 or 2 minifig packs.
In fact, at least Castle gets the humans and skeletons battle packs, but unfortunately they are not available to all countries!