Voter turnout was low for two similar reasons: no one believed their vote would actually count, and if they did step outside to the polls, they risked getting arrested for being a dissident. Ever since young activists spurred record turnout in 2019, Beijing has ensured that, no matter how obviously fraudulent it looked to the rest of the world, Hong Kong would never again conduct a free and fair election. This has not only kept voters on the island from heading to the polls but some opposition leaders from wanting to return home from abroad.
Beijing tightened candidacy criteria to prevent politicians in cahoots with Western nations from sneaking into office to undermine China and its territories. Beijing also isn't lying about the historically low voter turnout but rather knows that it will take time for the population to understand the importance of excluding traitorous candidates from gaining power. Western-funded outlets like the BBC and VOA are only focusing on Hong Kong's low turnout because they know their own countries' elections are just as "corrupt" as they accuse Beijing of being.