Not trying to belabor the point, but Cato's suicide (death for honor and principle, akin to samurai) seems to be of different category. But I've no horse in this race, so sure, Seneca's point that "the way out lies open" is certainly valid - after all, perhaps in his view, any death, freeing as it is, is acceptable. Indeed, death comes quickly and it could come more quickly yet! - and that seems to be key to understanding more about life.