They're both good. And of course it depends where the frn is from, as Golden's is a little slippery and tends to look more plastic-y, while seki's is gorgeously textured and all the seams are hidden.
They're both very strong, but g-10 flexes very little if at all, while frn flexes freely. G-10 has more textural variation and can generally look better when smoothed out, but frn can be molded freely and easily, and texture can be simply molded in. Frn is cheaper, G10 is more ding and heat resistant.
It's like comparing G-10 and Micarta. They're both good and are better at different things. Although I agree with the sentiment that in the modern age there's very little reason to stop moving forward in material technology.
I require more lc200n and thinner grinds
Current collection: Watu, Spydiechef, Native G10 salt, Waterway, K390 Ladybug, Caribbean