http://whirtorrgetftvz4g466sjqkegtyi35bjl4bvotfkfossunf5my4x6ad.onion/blog/bitcoin-tumbling
Most of the tumbling services and platforms face problems either from the side of regulators and politicians or through exploitation and hacks. Some of them were even pure scams that tried to rip off their users. Trust is especially necessary with the centralised tumblers, while decentralised usually face problems such as higher transaction fees, slower transaction processing or more complicated interface.