Keep in mind beach farm has over a 42% chance of getting trash or seaweed when you fish, and the riverlands farm gets bubbles which no other map type does. Also river fish include catfish, and the ability to grab those early spring rainy days just by walking out your front door, fishing, and throwing stuff directly into your shipping bin, is a nontrivial boost to early income (be sure to buy some salads or trout soup ahead of time when you see the weather). It's especially ridiculous in 1.6 with an early bait-maker so you can fish almost nothing BUT catfish all day long. And, just personally speaking, the bridges-connecting-tiny-islands is easily my favorite aesthetic out of all the farms. Space? That's what Ginger Island is for.
All the farm types have stuff going for them and are worth playing at least once, but if you want a fishing-focused run even without the free fish smoker the Riverlands farm is strongly worth considering.