As the paraphrased saying goes:
“If you outlaw Encryption only outlaws will have Encryption.”
It doesn’t solve a thing, other than make politicians look like they are doing something.
Petty thieves, small time drug dealers and other small time criminals may end up without encryption. But it doesn’t solve organised crime, there are the problem and they are intelligent enough to use an encrypted app, even if it “illegal”.
Amusingly our politicians all seem to run our government and parliament via WhatsApp and that’s obviously E2EE.