Quick take
Often yes, but not automatically. Compare the exact system recovery claim and account for automatic flushing rather than assuming every tankless unit is efficient.
Why tankless can improve recovery
Integrated booster pumps maintain membrane pressure, while larger high-output membranes produce more permeate per unit time. Both can improve practical efficiency.
Why flush cycles matter
Tankless systems commonly auto-flush to protect the membrane. That is useful maintenance but adds drain water outside normal dispensing.
Traditional systems can still be efficient
A well-designed tank system with good pressure, a permeate pump or efficient membrane can perform much better than an old generic 3-to-1 waste stereotype.
What to compare before buying
Use exact recovery data, membrane replacement cost, annual filter cost and real daily volume together.