P2P cannot give as much money as a crypto exchange can. For example, Carl The Moon has more than a few hundred million dollars and never hides from anyone. Why should an ordinary citizen be afraid of someone with a maximum of 0.10 BTC in their wallet?
That's a pretty stupid statement. Satoshi could send an email to Adam Back tomorrow, negotiate a P2P trade with him for 1 million BTC, at a price that satoshi wants and Back can pay; they will meet and make the trade P2P. No problem.
Besides the fact that your first statement ('P2P trading can't have as much volume as a centralized exchange') has nothing to do with your second one (something about hiding how much you own):
There are very legitimate reasons for not wanting everyone to know how much you own. For instance, not wanting to be attacked, killed and robbed.
Besides, P2P trading is not only about minimizing the amount of people that know how much you own. Here's an excerpt of things that
decentralized P2P exchanges like Bisq generally do better than centralized ones.
- No KYC required. Read: [Why KYC is extremely dangerous – and useless]. Your documents can be stolen or 'lost' and used in actual crimes.
- Less trust required. Centralized exchanges can and do freeze funds, so every time you deposit money you cannot know if it will be credited to your account or deemed 'illicit' (even though you did nothing wrong) and just stolen from you. You also don't need to trust them to keep your KYC documents safe.
- It is decentralized. This means a variety of things, but some of them: [1] Censorship-resistant - governments or other powerful entities can't just shut it down. [2] No central point of failure (hardware attack / hostile company takeover etc.). [3] No business behind it that may be interested in exit-scamming their users. List goes on...
- As just alluded to; there's a huge list of exchanges that went off the radar or claimed being hacked of all of their funds, where it's clear they effectively stole those funds.
- Related to above point: Centralized exchanges always try to make you leave your coins with them. It is sometimes extremely expensive (e.g. $20 withdrawal fee) to actually get those BTC you bought into a wallet you actually own. As long as you don't withdraw, the exchange could be offline, it could geo-block your country, it could block your IP for 'illicit reasons' (something that can always be claimed, no matter if you did something illicit or not - keep this in mind), the exchange could claim your funds came from a crime, it could claim it was hacked and lost your funds, and the list goes on. Not being able to cheaply withdraw (read: actually get what you paid for) is a HUGE issue with centralized exchanges. Keeping funds on them should be seen as an 'optional service' and not the encouraged default.