I've learnt that water can dissolve ionic bonds because it possesses a high dielectric constant.

In the cases of covalent compounds (especially the non-polar covalent compounds), where the molecules are held together by mainly van der Waals forces of attraction. They are said to possess a higher dielectric constant.

In the case of inoic compounds where they are held together by electrostatic force of attracrion, water is a solvent that can dissolve almost all the ionic compounds ,the reason stating it to have "high dielectric constant".

Then why is that covalent compounds cannot be dissolved by an ionic solvent such as water? And is there any connection to this topic as to how most of the non-polar covalent compounds are immiscible in ionic solvents?