If they both form hydrogen bonds, Why does borax make polyvinyl alcohol slimy/elastic but water doesn't?

When dissolved borax (borate ions) and polyvinyl alcohol are mixed, an elastic slime is formed. To my understanding, this is because the borate ions form hydrogen bonds with the OH groups on the PVA, cross-linking the polymer chains and increasing elasticity.


However, on a page discussing slime (<https://www.acs.org/content/acs/en/education/whatischemistry/adventures-in-chemistry/experiments/slime.html>) the American Chemical society states that "Water is an important ingredient in slime. Water helps the polymer molecules slide past each other so that your slime can flow. "


Water would presumably also form hydrogen bonds with the PVA polymer - so my question is, why do borate ions increase elasticity while water increases liquidity?


