The article is very poor mixing the actual charges with unrelated European Union concerns. The charges are not linked to encryption. Most of Telegram is unencrypted anyway.

The issue is with Telegram non cooperation and lack of moderation of publicly available content.

Your cell phone provider will cooperate with the authorities immediately and without question.

Cell phones are encrypted over the air, but they aren't end to end encrypted, and it's safe to assume that a provider will wiretap the plaintext passing through their backend if the authorities ask for it.

Telegram is not end-to-end encrypted in the way other messaging services are (whatsapp, signal), it is encrypted but Telegram holds the keys and are able to decrypt any messages not sent on a "secret chat" which is not the default, or any messages on a group chat

Telegram not being fully encrypted and seeing the content of most messages on its servers but not cooperating with the police?

The cell phone providers aren't likely refusing to cooperate with the authorities in whose jurisdiction they operate.

If a warrant exists they hand over all your data and even wiretap you.