The WT doctrines are hardly a 'clearer understanding' of the texts of the Bible. Theirs, like all church doctrines depend upon selective reading and eisegesis. The Catholic church at least has a core tenet that revelation is progressive, (Progressive revelation (Christianity) - Wikipedia) that is actually a much more mature approach to the diverse collection of writings in the Bible. The WT basically glosses the writings and misses or disregards the changing character of Judaism and later Christianity.
Ironically, they then use a similar progressive revelation excuse for their own adjustments in doctrine.