Audacity is not more convenient. Not by a mile. Voice actors have tons of workflows that only a DAW can help with.

"Only recording lines"? There may be more to it than you think.

I use Ardour when I do sound design. A lot of the time you want to be able to automate volume changes, or add a reverb or an EQ(With real-time controls instead of the annoying batch "Change it, then test it" workflow), etc.