Owtch, now you've got me thinking about Bjork, Post, track 8.
oPossum's reply made me think some more.
Meanwell is not famous because it makes the best power supplies ever, but because they make a very reasonable quality power supplies for a very competitive price.
Ripple currents on the primary side are 20x lower then on the secondary side, (for 240V -> 12V) which means that internal heating by ESR currents is 400x lower, physical size of high voltage caps is probably larger, so more cooling for the Elco, and I think higher voltage Elco's also tend to have a lower ESR.
[Edit]
Confirmed by the ESR tables in this thread:
https://www.eevblog.com/forum/beginners/esr-values-for-electrolytic-caps/[/Edit]
So it looks like Meanwell knows where they can save money.
I dunno about Lelon, but my hat of for Meanwell.