I know everyone is entitled to their own opinion, but I feel the downplay on Boa Hancock is pretty unfounded and is solely displayed by her actions in filler or lack of action canon-wise.
Let go through points that some people frequently overlook:
Boa Hancock hails from an island that is filled with Amazonian warriors trained at a young age and are all taught with the use of Armament and Observation Haki. It is said on Amazon Lily that Strength = Beauty. If that holds up, Hancock is extremely strong!
Boa Hancock’s initial bounty after her first campaign was 80,000,000 Berries and the World Government feared her power so much that she was offered to join the Shichibukai at the age of 18.
In comparison, Luffy’s starting bounty was 30,000,000 Berries. Both Sengoku and Kuzan have commented on how powerful she was and not to be underestimated. This is highlighted by the fact that when former Admiral Aokiji stabbed Luffy in the arm with an ice spear, she was ready to fight him before Marco interfered.
Also during Marineford, she casually took out Pacifistas with ease when prior to the timeskip it took the whole Straw Hat crew to defeat 1. Not only that, she managed to hold off Smoker and Sentomaru (who can use Advanced Armament Haki) from advancing towards the Plaza to engage in the fight ahead. Another noteworthy feat, she’s one of the few people to leave Marineford completely unscathed.
She’s is one of the very small number of people in the world who can use all three types of Haki (Armament, Observation and Conqueror’s). I don’t think Oda would expose that kind of detail about Hancock without backing it up about her power.
Seriously, I would not be surprised if she had awakened her Devil Fruit abilities, knows the Advanced forms of Haki, has future vision (high/top tiers should have this ability moving forward), and very strong Conqueror’s Haki. It just depends on how Oda deals with the mystery and hype around her.