However, when it comes to trading, regardless of all the decentralized options, we still have the "problem" that we have to use centralized services when it comes to the deposit/withdraw of fiat funds
You definitely don't have to. I've traded bitcoin exclusively peer to peer for years, and it is easier today than it has ever been before.
Of course, there is always the possibility of face-to-face trading, but that brings with it some other risks that many do not agree to.
I hear this repeated a lot on the forum, yet I've never had a single issue with face to face trades. As long as you are using a proper P2P exchange such as Bisq to set up the trade and not just finding some random scammer via social media, and you take standard security measures, then you are no more at risk from a face to face trade than you are any time you go out in public:
You are really at no more risk than you are most of the time you go out in public. Anyone on the street could be a criminal out to rob you. People carry cash, bank cards, a mobile phone, jewellery, keys for their car, keys for their house (with their address probably visible on some piece of ID in their wallet), tablets, laptops, and all manner of valuable objects. Lots of things which are far more valuable than a few hundred bucks of bitcoin.
Every time you use an ATM, someone could be waiting with a weapon to relieve of your cash. Every time you step out of a store, someone could rob you of whatever you just bought. Every time you park your car, someone could beat you up for your keys and ride off. A face to face bitcoin trade is really no different.
Take standard precautions and you will be quite safe:
- Choose a highly rated trading partner
- Don't share unnecessary personal info
- Obscure your appearance (easily done in this time of face masks for everyone)
- Arrange your meeting during the day in a busy public location - choose somewhere with CCTV if you want, like a large shopping mall
- Bring a friend with you
- Only bring the amount of money (bitcoin or fiat) that you are trading
- If legal in your jurisdiction, bring some kind of weapon for self defense
In some sense, CEXs are safer because you're dealing with a "trusted entity".
Remind me what is "trusted" about CEXs, exactly? Literally every single one has experienced data leaks or hacks in the past. Dozens have exit scammed. Dozens have gone bankrupt. Dozens more were simply corrupt from the start. More have shutdown. More are currently be fined billions of dollars for illegal behavior. All have arbitrarily locked accounts and frozen coins. They've been caught insider trading, stealing your money, dumping their own bags on their users, listing scams, running fractional reserve, and more. And if you are lucky enough to avoid all of that, you get absolutely ripped off with outrageous fees.
I trust any one of my peer to peer trading partners exponentially more than I trusted the sheer greed of centralized exchanges.