I don't play cities so I cannot speak for that, but for figures:
(1) much less effort to learn comparing to echoes to play at a reasonable/mediocre level (depends on how you define the level)
(2) more fun than echoes
(3) the strategy does change a lot
Unlike echoes, I don't think you have to be very familiar with figures cards to play or enjoy. This is because there is no way to draw them consistently so it is almost impossible (at least I haven't figured out a way) to hunt for the card you want efficiently. It is more like seeing what you get and try to make best use of it. Also unlike echoes which was created with a different rule set in mind, there are less broken cards or broken strategies (ie, stack and splay FTW!)
One fun aspect is that some mediocre cards becomes pretty good at later stage in game because sharing them draw you a figures card. Icon dominance is less important as well for the same reason as well as lots of "attacking" effects are not written as demands and sometimes are not even sharable by being inspires.
That being said, it still helps to have a rough idea how each stack of figure cards is behaving. For me, it is really important to know that early figure cards are really hit & miss so it doesn't really matter that much if you are drawing them or not. There are helpful cards in age 3 and 4 but no big game changers I think. Age 5 is monster though, so try to set up your board so that you can start to draw them when you reaches the age, or to make sure your opponent cannot draw them easily when he is there.
Anyway, back to the original topic, I think figures is plainly more fun to play than echoes, especially for new players. Stop worrying and wreck some fun!