It depends on who you're targeting - in my experience, agencies and SaaS founders are inundated with cold DMs, but if you have a unique DM strategy, then you'd definitely stand out!
When your message and timing is relevant, any channel will work. LinkedIn is no exception, it always works better when you are already connected and your contact has some idea of what you do and how expert you are (c.f. @byalexai relevant post below). I have done it in the past.
I think a lot of factors matter: the level of your personal account, your message, your product. So for some it will work great, but for others it won't.
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