Who puts money in banks? People are turning towards investment companies, which are real, live Iskos.
Not everyone held of the Heter Iska. The Shla Hakadosh was famously against it. He said Hashem knows what you are doing, even after the fancy trick.
It seems to boil down to a Machlokes if Ribis is a moral issue, in which we care about the ‘spirit of the law’, or if it is merely a Chok that once circumvented is not being transgressed. By an Assei you can be Mehader and look to be Mekayem, as in putting on a four-cornered garment to require Tzitzis, but when there is no Lav there is nothing to be Mehader about (unless it has a Rei’ach Aveira).