I think people are way obsessed with strength measured only in physical excellence. If Ging could use Breath of the Archangel at will and is only medicore at fighting, he'd still be considered a living God and would rightfully deserve the top 5 ranking. It's the top 5 aura users of the world, not the semi finalists of the Martal Arts Olympiad at the Celestial Tower. One of the key points about Hunters is that they're definitely not very good at killing people anymore, probably because they've grown lax in their years of unrivaled dominance.
It's quite clear that the wealth and status the Hunters enjoy indeed must have made them weak and corrupt at some level. The wealth and status of Hunters is absolutely unimagineable. If the Spiders pooled their money together they'd still have a hard time having enough money to buy a copy of GI. Okay so you can say Spiders just take whatever they want, except they obviously weren't able to get a copy of GI until it showed up on the Yorknew auction, and quite a few members of the Spiders were actually interested in playing GI. Yet a random Hunter donated 6 copies of the GI game for free. Neither Zeno nor Silva really likes to kill people, and we can gather they do what they do because it's needed to support their lifestyles. And how rich are the Z family? Well Miluki asked for a loan of 15 billion zenny from Silva to buy GI in exchange for killing 10 people for him, so we can assume this amount of money is nontrivial to them. The 6 copies of GI sold for well over 100 billion zenny at the auction and it was donated by a single nondescript Hunter, and we can be pretty sure that guy isn't even anyone special amongst Hunters. If you have money that makes the Z family look poor, why would you ever want to risk your life? After all, hiring the world's best assassin is probably only pocket change to these guys.
That said based on the Election Arc, the fighting prowess of the Hunters as an organization literally fall off a cliff after Netero died. Or maybe the point is that Hunters have grown so fat that they're no longer capable of fighting for what's right and that they're so pathetic, Pariston was forced to abandon whatever evil plan he had because it'd be totally shameful to pick on such a dysfunctional organization.
---------- Post added at 12:50 PM ---------- Previous post was at 12:36 PM ----------
For Meryem playing these games, they're just games. It's not like he's devoting any special effort to them (aside from Gungi). It's literally something he's doing because he's bored. The country he's in has a population of 5 million people, so you try to pick up an instruction booklet on something you've never played before and beat the best guy out of 5 million in under a day. How good is Meryem at games? Before Meryem, nobody ever pushed Komugi to use aura. That is, although she is capable of using aura, she clearly never had the need to use it before which is why she's surprised she even has that ability when it was awakened. Although aura tends to be limited fighting in HXH, it's clearly applicable in all other fields too. If someone uses aura in a game, he must enjoy the same near inviniciblity against anyone not using aura similar to physical fighting. Note that 'using aura' means you've aura especially tuned for game playing. There might be plenty of people who can use aura generally but as far as we know Komugi is the only character who have aura specifically tuned for Gungi, because otherwise that'd mean any random guy capable of using aura (say Gon or Hisoka) would suddenly become a Gungi champ if they decided to enter a tournament.
So although Meryem has no aura-related game playing abilities, he was able to push the world champion of Gungi into using aura, which is something she's never done before. This pretty much means at that point, Meryem would easily be able to crush anybody she has defeated before, as she didn't need aura at all to get her world champion title. Komugi's dominance in the field of Gungi is every bit as dominating, if not more so, than Netero's dominance in the field of martial arts. So it took someone that's equivalent of Netero in his prime (Komugi is obviously in her prime in terms of Gungi skill) to beat Meryem in a game, and it's clear such individual excellence is exceedingly rare.
