Only in the case that it would prevent you from fulfilling everyday responsibilities. But I think that most activities that can be addictive (don’t have to be), will lead to unproductive ends.
Other very natural things such as having conversations with people or going to the gym too often are also unproductive & I’d put them under the same category.
Personally, however, I think that masturbation — and all sexuality activity — is completely reasonable and should be expected/ encouraged for various different biological reasons that u probably know about off the top of my head and that I’d have to reference and look into.
It’s good to clarify on that, so thanks for bringing it up.