Even though bug catching is pretty simple, I tend to like fishing more. I find that most common fish sell even more than the common bugs that spawn. In the summer, bug catching because beetles. Just depends on my mood but I like fishing more.
Fishing, only bc I'm bad at catching bugs. I either scare them away or my accuracy is way off. However, I like catching beetles on the island. Occasionally I get lucky lol
I prefer bug catching, but mainly only at the island for all the cash you can get. I also usually do more fishing at my town, but I don't really do either unless at the island and I'm trying to make bells.
Fishing is somewhat more enjoyable but the need to tap the button instantly on rare fish drives me nuts. Basically can't catch anything rare unless I close my eyes and listen for the sound instead. Fish are on average much more profitable too.
Bugs are arguably more interesting to catch because you can actually see them walking, flying or sitting around in their natural habitat, and each bug has its own sort of strategy and behaviour. The downside is many rare bugs don't even sell for 1,000 Bells...
I adore fishing! But maybe that's because I also love fishing in reality too? It's just so much fun for me and I love surprises I get and stalking the fish shadows.
That and I seem to be really terrible at bug catching. I can do semi okay, but overall it's more frustrating than fun for me.
I really can't stand fishing. I used to get an itchy trigger finger when watching it approach the bobber so I often pressed A too early out of anticipation. Closing your eyes and listening definitely helps, but I still get annoyed when some fish constantly switch directions, and when I finally land the bobber in front of it, it does like... One little nibble and is like "lol nah". And it starts swimming around again. Srsly m8 y
Fishing can be better because they are much easier to find than bugs but they can be pretty hard to catch if it's a large or a fast fish and not to mention that fishing is kinda buggy in some of the games (especially the N64/GCN games where they go for the bobber, bite and then go right though the bobber or when they just don't even notice it despite the bobber being right in-front of them).
Bug catching can be better because they are much easier to catch than fish but they aren't as common as fish especially during the winter. Also, I feel like the hitbox on the rental net has been heavily toned down since the Welcome amiibo update. Before the Welcome amiibo update I used to be able to hit the tree no matter how close I was and I would always catch them, now ever since the update I have to be at a certain distance otherwise the net hits the top of the tree and the bugs would fly away.
In conclusion, I seriously do not know which is better. Both have their ups and downs.