I’m not a big trader, but people send me BTC about once per week. It takes 30 minutes easily to get the transaction confirmed on the blockchain. Before that, it’s not clear the transaction is legit. And I have had one or two transactions that don’t reach the magic number of 6 confirmations. I’m not sure how the sender pulls that off, but I alert them of it, don’t deliver the goods, and they haven’t complained (knowing they sent a fraudulent transaction? I don’t know)
It’s my understanding those confirmations are being done by miners who get a small fee that me or the sender’s pay.I see this labeled as “network fee”.
The 30 minute wait would only make sense if you were to trade USDT for bitcoin on a CEX, then send that money using bitcoin to another CEX to execute the next trade to USDC.
I'm not sure what he is talking about. On centralized exchangers execution, confirmation, and settlement happen nearly instantly. Unlike with stocks there is no 2 day settlement time.
For decentralized exchanges you can do it in 1 transaction executing both trades atomically. Modern token swaps will look for the optimal series of trades to make from available DEXs to give you the best rate. It can automatically check if it's better to go straight from USDT to USDC or if it's better to swap to bitcoin first. Sometimes it makes sense to split it up so some of it is direct swap and the other part of it uses an extra leg to get a better deal.