Papered fins looks like crap when you don’t do it correctly. And when done correctly, it not only looks great, it does add strength. I’ve tested a papered fin to a plain balsa fin. Easy to snap balsa along the grain. Not as easy when papered.
I’ve seen recommendations to use Avery label paper, but I don’t think the adhesive is sufficiently sticky to stay stuck to fins. I prefer Mod Podge since it looks like white glue, but it brushes on smoothly. Finally, I think the secret to getting super-flat, super-smooth fins when papering them, is to press them flat while drying. Papering fins adds moisture to the paper. Glass plates and plenty of weight helps eliminate any wrinkles, waves, or irregularities caused by the moisture.
Doing something the “traditional” way does not make it better, it all depends on application. And should you think I paper all my fins, and therefore a “papering snob”, I only paper occasionally. I’m a huge fan of Brodak sanding dealer and use it 95% of the time to fill grain. I just like to try different techniques.
If you take your time, filling balsa grain on fins with sanding sealers, or papering your fins, can yield similarly excellent results. No one way is necessarily better, it’s just different. Some builders, like John Boren of Estes, use Bondo Spot Putty to fill grain, and use lots of coats of filling primer, prior to painting. His finished models look pretty good.