Why do acids and bases donate/accept proton?

[Jasmine 2C]

Acids and bases, is there a reason why these compounds want to accept/donate a proton? Doing so causes their molecule to be less stable so why do it? Why gain a positive or negative charge when you can remain stable at net charge = 0?
This question kind of came up from me trying to understand why KOH would accept a proton and not donate the proton it has.

[Chem_Mod]

When you dissolve ionic compounds in water, the sheer amount of water molecules makes it more favorable for the compound to dissolve into its respective cation and anion. This is because many water molecules can interact with one ion at once, which releases a lot more energy than if the ions were to only stay bonded to each other. In the case of KOH, it will dissolve into K+ and OH-. I am not sure why you think it would be favorable for OH- to lose its proton, as it would then become even more negatively charged.

Please also give your post an informative title next time