The feeling of being wrapped in warm waters, comforted in peace and love is intrinsic to all of humanity. It's our primal memory. Water is indefinable and formless and feels rational and irrational. It can freeze and shock just as easily as it can comfort and purify.
Del Toro's "The Shape of Water" leans into these truisms through the lens of midcentury cinema, with glorious production design and performances to match. If Douglas Sirk had ever gotten the budget to make a "Creature Feature" for the local drive-in, I suspect we might've gotten something quite similar. The lush colors, the female protagonist filled with longing, the centering of "the help", all are right here and in period costume to boot.
There is even a dream ballet!
I would not be surprised if Michael Shannon mainlined Nicholas Ray's Bigger than Life (1956) before taking on this role. His pill-popping, ever more psychotic character is pure James Mason (they even kind of look alike). Sally Hawkins has the energy and expressions of a Lilian Gish, and accomplishes so much with so little dialogue.
So if the film is a bit on the nose, and a bit obvious with its politics and heart, all is forgiven.
We should all have more mid-century style fantasies in our lives.