If i understand correctly what the 2% is referring to is the channels on Amboss.space marketplace where you get the money up front, the APY doesent come from the fees and the payments you route through a channel over time afaik because the channel fee is set to 0. so its a different model than the traditional one.
here is the quote
I'm watching the effect of Zero Fee Routing's management strategy really take off and inspire others to do the same. With zero routing fees, we're seeing more people choose to frontload their routing earnings through channel sales on Magma, which is something that we can verify. 2+% APY is pretty good and that's before any income that they'd make from actually routing!