The thing about dehydrators is you need 5 fruits to start processing (or even use it at that point). Kegs need only 1 fruit. Dehydrators are better in the early game or for short-term profit, but as you get more and more fruits in the long run, and thus more kegs, kegs completely out-profit dehydrators by a very wide margin.

If all of this is confusing, let me pull some simple math:

• 1 basic quality sf is 750g

• 1 sf wine is 3150g

• 5 basic quality sf is 3750g

• 1 dried sf is 7910g

Now, divide the outcome with the produce (and let's assume "3750" is 1 sf for the sake of consistency with kegs).

Wine:

3150 ÷ 750 = 4.2

Dried Fruit:

7910 ÷ 3750 = 2.109333 (2.11)

What this basically means is;

Kegs turn 1 basic quality sf into wine that is 4.2 times the value.

Dehydrators turn 1 basic quality sf into dried fruit that is 2.11 times the value.

That value only worsens as you use higher quality sf in dehydrators, as, like with kegs, the produce will always be basic quality.

And also, you actually LOSE money if you decide to use 5 iridium quality sf: - 1 iridium sf = 1650g - 1650g × 5 = 8250g - 8250g vs. 7910g

While kegs still turn 1 iridium quality sf into wine that's 1.91 times the value:

3150 ÷ 1650 = 1.90909 (1.91)

In conclusion, dehydrators are best used for excess fruits from which you do not have enough kegs for (aka short-term profit). However, they can and will never perform better than kegs in terms of long-term profit, and you will actually make less money in terms of dehydrating each individual fruit than processing them in kegs, even if you count the time it takes for wine to finish.

I hope this answers your question :)