I could flip the table and ask why use 30# and up?
Of course there are reasons, and techniques like flipping
in thick cover, etc. But like @NHBull, those aren't things
I do much, if any of. I've never seen the need for 60-80#
line, but plenty use 'em. In the end we use what we feel
comfortable/confident with.
10 and 15# braid are my staples on spinning gear, and 20
is on my casting gear (and always with a leader) For one,
line management is better on spinning, for which I use 1000
size reels. I can fit more on them than if I used 30. And yes,
I've used 30 and 40# braid in years past, just prefer thinner
lines....
As for 20 on casting, yes, it is light, and there can be issues
with dig-in, but in my use, I'm keenly aware of that fact
and always take off line if I've fought a big bass, or pulled
in a log. I'm truly amazed at how strong 10, 15, and 20#
braid is. Stronger than we think, I'd wager.
