Oscar is about 5.  I switched her to canned food from dry almost
exactly one year ago.

For some reason, I can't find any of the links I know I read when
making this decision.

Here are the reasons I switched Oscar to canned food.  Note that these
are just things I have read; I'm not a vet or an animal nutritionist.
Certainly there are people out there supporting both canned and dry,
as well as others who support raw diets, home made diets, etc.

Anyway.

Hydration.  Cats typically don't drink much water; in the wild, they
get water from eating their prey.  So they tend to get dehydrated when
on a dry food diet, leading to bladder and kidney problems.  Canned
food is just one more way to get more liquid into them.

Carbs.  Cats are on an enforced Atkins diet; carbs in large amounts are
bad for them.  The technical term is "obligate carnivore."  Dry food has
way more carbs than wet food (especially if you seek out wet food that
doesn't use rice, etc for filler).  Because cats need fat and protein,
not carbs, they tend to overeat on dry food because they aren't getting
the nutrients they need.  Then their owners put them on diet food, which
has even less fat and protein, and it's even worse.  Dry food is like
kitty potato chips -- filler.  My vet believes that dry food is the
culprit in many cases of feline diabetes, and has gotten several
patients off of insulin by switching them to a non-dry diet.

The myth of clean teeth.  I always thought that cats benefitted from
getting their teeth "scrubbed" by kibble, but as it turns out, they
don't chew in such a way as to get much benefit from that.

My own experience.  When I switched Oscar from dry to wet, the change
was profound.  She lost quite a bit of weight, and went from "fluffy" to
well-proportioned.  She became noticably more energetic, doing things I
only associated with her kitten-era self.  And when I did give her a dry
food meal after a long time on wet, she sat around all day, looking like
she felt miserable, with nasty noises coming from her tummy.  

I feel like there are a bunch of other reasons I'm forgetting, but
there's a start ...

Anyway, Oscar really didn't care for canned food at first.  Even now,
she only likes certain flavors of certain brands.  But over the course
of a year, I've gotten her to actually clean her plate enthusiastically.
If your cat absolutely won't eat and is starving rather than eating dry,
then yes, I'd feed dry.  But missing one meal won't kill them.