If a creature loses all abilities, does it lose static abilities granted by other permanents?

When an effect says a creature "loses all abilities," it removes only the abilities that the creature itself currently possesses as part of its own text box (or previously granted abilities that have been copied onto it). This is governed by CR 112.1, which defines abilities as existing on objects, and CR 613, which covers the layer system for continuous effects.

Static abilities on other permanents (like an Aura enchanting the creature, an Equipment attached to it, or a global anthem like Honor of the Pure) are not abilities of the creature — they are abilities of those other permanents. Those permanents' effects continuously apply and grant bonuses or abilities to the creature regardless of whether the creature has "lost all abilities" (CR 611.3b, 613.1d).

This means if a creature with a +1/+1-granting Aura attached to it loses all abilities, the Aura's static ability still functions and still modifies the creature's power and toughness, because it originates from the Aura, not from the creature itself.

Example: Your Grizzly Bears (2/2) has Curiosity (an Aura) attached. Your opponent activates an effect that makes Grizzly Bears lose all abilities. Grizzly Bears loses its own abilities (none relevant here), but Curiosity's static ability — granting "whenever this creature deals damage to an opponent, draw a card" — still applies, because that ability belongs to Curiosity, not to Grizzly Bears.

The key distinction: "loses all abilities" strips the creature's own ability box, but other permanents' continuous effects operate independently under the layer system and keep applying their modifications to the creature.