According to page 8 of the Bitcoin whitepaper, if a single miner has more than 45% of hashpower (as Antpool likely does). We should be requiring upwards of 300 block confirmations to reduce the probability of a reorg to 0.1% for that transaction.

Since there are miners with ~50% hashrate, anyone who only accepts a tx after only 3-6 confs is still facing a 20-30% probability that their tx could be undone by the miner (if the miner wanted to).

Therefore, Bitcoin is not a trustless system. Because most users trust the largest miner to not reorg. Under current circumstances, using bitcoin in a trustless way would require waiting almost 2 days after a tx confirms (roughly 300 blocks) before calling the tx finalized.