While I agree to what you're saying, the use of Arabic is not disappearing in the rest of the Arab world as in parts of Lebanon. Some Lebanese see themselves as "non-Arabs", when Lebanese are nothing but Arabs. Those who are in an identity struggle are using French and English mostly, and can't speak Arabic well. I have Lebanese relatives, and some words they say in Arabic are really heavy Arabic words that even we don't use. They still avoid saying that it is indeed, Arabic.

I am Palestinian-Jordanian and I do understand almost all slang accents fairly well. The only one I have trouble with is the Moroccan/Algerian. I understand it as long as they do not inject French or Berber words and speak slowly.

The levant accents are extremely similar that the gulf cannot really differentiate between Syrian, Jordanian, Lebanese and Palestinian (although we see them as distinct and can pick up which accent is spoken from just a word or two). The same phenomenon is seen in the gulf. Iraq is pretty distinct, yet closer to the gulf. Everyone understands Egypt as it is pretty close to Standard Arabic (just like the Levant), although its quirks have become known through songs, movies and shows which are dominated by Egyptians.

As for Standard (or Classical) Arabic, everyone in Jordan (or most of the Arab world) who went through some sort of schooling can speak it, and understand it perfectly. The news, newspapers and any formal event is given in proper Arabic. All Arabic literature, books, and writings are also in Standard Arabic.

My point is, while I agree with you that the use of Arabic is degrading, I doubt it will ever be overtaken by French or English (depending on where you live). English and French are being seen as a symbol of being educated, and those who are uneducated try to speak English or French (albeit terribly). Some who like to show off, or have some sort of identity struggle, rely heavily on French or English. Outside of these insecurities, Arabic is pretty much always in use.