There are many levels of estimation, including budgeting, high-level estimation, and task planning (detailed estimation). We can link a more classic view of estimation to the Agile planning onion - strategic planning is the outer layer and the planning that occurs in the daily sprint meetings is at the core. Each layer closer to the core relates more to a team’s day-to-day activity. The #NoEstimates movement eschews developing story or task-level estimates, and as you get closer to the core of the planning onion, the case for #NoEstimates becomes more compelling.
This presentation discusses the differences between budgeting, planning, and estimation, as applied to testing in an Agile environment, and when each technique makes sense, when they don't, and in what combination for testing.