I double up the bags with holes. Tie the handles then toss that handles down into a third bag. Kitty litter remains secure.
I do agree the quality of those bags has gone downhill. It's like we're forced to make them single use only.
Another solution to grocery bags that are too thin and holy to reliably hold kitty litter:
Get rid of the cat.
The old cat was a constant food eating, litty consuming, urine-feces-hair-dander generating furball.
Humanely paid Petco cat placement lady a $100 donation to guarantee finding kitty a home.
Problem solved.