Honestly, I really think a lot of people are gonna have different experiences because I believe that the type of document one is verifying with also contributes greatly to how long and easy the verification process would go or last, for example, the experience one applying for a kyc verification with a plain id card will likely be different from one applying for the same with an international passport.

On the note above, i will like to let the op and everyone else know the exchanges am currently verified on and how long it took -
Binance exchange - less than 1 hour and on first trial.
Kucoin exchange - less than 30 minutes and on first trial.
Gate.io exchange - less than 1 hour and on first trial.
Mexc exchange  - no longer sure how longer this took but i guess its less than an hour and on first trial.
Digifinex exchange - almost 24 hours after second trial.
Xt.com exchange - more than 3 days after third trial.
Remitano exchange  - less than 5 minutes and on first trial.

It might also interest you all to know that i used the same document for verification on all this exchanges, which my drivers license.