Convenience I will grant you. Although I would argue onboarding to a new DEX such as LocalCryptos is significantly easier than onboarding to a new CEX such as Binance (literally just make an account versus make an account, hand over all your personal details, upload scans of your documents, take selfies, wait several days for verification, link a bank account, deposit fiat, wait several days for it to clear), when trading fiat/bitcoin pairs then a CEX will always have the upper hand in terms of transaction speed because of the slowness of the fiat banking system. Maybe once CBDCs come along and you can move fiat instantly between users that will change. Bitcoin/altcoin pairs are a different matter and can already be traded instantly on DEXs.
The "feeling of safety" I don't disagree with, but it's worth pointing out that that is very much a feeling as opposed to being grounded in fact. Centralized exchanges have been responsible for far more scams, hacks, thefts, and losses, then DEXs have been. Given that you do not either provide your personal information nor deposit your coins to a good DEX, they are inherently far more secure than a CEX, since there is simply nothing to be hacked or stolen from their platform. If you only choose to trade with trusted users and follow all the recommendations regarding escrows, communication, release of funds, etc., then you chance of being scammed is tiny.
I think the onboarding process seems easier only to us, just like how using a Bitcoin wallet to sign and choose inputs and select fees seems easy to us... but to most other people, having a mobile app. I think of the exchanges that people use here which is not so much binance but like tokenize or luno which I use, I know most people never heard it but everyone here uses it because it has a license (unlike Binance), an app that can "instant exchange" local payment method to crypto and vice versa in a few taps.
The KYC is linked to bank account so if you already have a bank account you just link and that is your kyc. It's very, very easy and convenient and instant. And it will get even easier between all apps where you can send ppl money and crypto using their phone number, imagine selecting your contact from yr phone to send crypto.
It's not real crypto of course but only people like us know that, but most people don't know and frankly don't care. I tried showing some people what a real Bitcoin wallet should look like and the look on their face is just disgust lol.