What is an idiom for saying that someone/something is as bad as someone/something else? [closed]

What is an idiom for saying that someone/something is as bad as someone/something else? For example, when someone praises a particular system but condemns the other, we may say that they are both bad and corrupted.

As noted by @Cascabel, your question is currently a bit unclear. However, if we interpret it as something like this:

John: System A is wonderful, and System B is horrible.
Eric: Actually, both systems are horrible. [insert idiom]

Then you could use the grass is always greener on the other side, or a variant.

From The Idioms:

Meaning:

• to think that other’s part is better than mine
• to believe that someone else’s life is better their own
• to think that the other person has it easier in a direct competition
• to think that own job is harder than someone else’s

Examples

Eric: Actually, both systems are terrible. The grass is just as stunted on the other side.

or

Eric: Actually, both systems are terrible. But I guess the grass is always greener [on the other side].

When someone praises a particular system but condemns the other, if we think they're pretty much equal, in practice, we can express this by saying

Six of one, half a dozen of the other.

Dictionary.com gives this meaning: "The alternatives are the same" and this example: “During rush hour, it's six of one, half a dozen of the other.”