A large order executed at once consumes the book and pays substantial impact. Split into pieces over time, each piece is small enough to be absorbed — but the market keeps moving while you work, and it may move against you.
That is the whole of execution, and no algorithm removes it. The choices only decide which side of it you take.
The two common schedules
Time-weighted execution spreads pieces evenly across a window. Volume-weighted execution trades more when the market is busy and less when it is quiet, so your participation stays roughly proportional to activity.
Volume-weighting is usually the better default because it concentrates trading where the liquidity is. In crypto, though, the volume profile is far flatter than in equities: there is no open and no close, so the intraday shape that volume-weighting exploits is much weaker.
What is specific to crypto
Continuous markets remove the deadline. An equity order must complete inside the session; a crypto order can be worked across days if the position warrants it. That is a genuine freedom and it is also how a small execution problem becomes a large position risk.
Multiple venues. Liquidity is fragmented, so working an order in one book while ignoring deeper liquidity elsewhere pays impact unnecessarily — and moving collateral between venues is neither instant nor free, the constraint from cross-venue arbitrage.
Your own footprint. A predictable schedule is readable. Trading a fixed size on a fixed interval in a thin book tells anyone watching what you will do next, which is the on-venue version of the visibility problem in MEV.
The honest measure
Against the price when you decided, not against the average you achieved. An execution that beat its own benchmark while the market ran away from you was not a good execution — it was a slow one measured against a moving target.