Identity view (i.e., "I am...") is the first lower fetter.
the mendicants who, with the ending of three fetters are stream-enterers
To say "I am the watcher" simply perpetuates identity view. Identity view is a conceptual tool. Like all tools, it can be put aside. When identity view is put aside, "there is watching." With identity view, there is a prioritization towards the self. Without identity view, broader consideration becomes the norm. With identity view, the self controls--there is struggle to use and impose will. Without identity view, experience unfolds effortlessly.
To see this, meditate "there is breathing" vs. "I am breathing". When "I am breathing" there comes a cascade of questions ("Am I breathing well?", "Should I exhale now?"). When "there is breathing", simple awareness follows the breath in and out. Effortlessly.
Relinquishing "I", we relinquish the first fetter. There is watching.