"Securely" being the key term here. Something that is buried securely today may not be buried securely tomorrow, or in 100 or a 1000 years, because the geology of the planet is not static. This can become even more of a problem if the knowledge should be lost what was buried where.
The subterranean geology of granitic shield provinces doesn't change much over the course of ...human-accessible timescales.
I agree to in way that this is currently the only viable way to handle the situation. But it is not a solution.
"Live in Idaho" isn't THE solution to deaths from tropical diseases; but let's not pretend that it isn't A solution...
But may not be better than shutting it all down.
Sorry, I like reliable electricity, I don't live near a hydro plant, and I'd prefer not to burn coal. Nuclear does what I want, and if the desire for a perfect solution for waste handling gets in the way of a good method for keeping the lights on while we work towards improving the isolation and transmutation of waste-that desire needs to be set aside.