A poor analogy depending on the setting because you can't adjust the odds with a slot machine, and the ROI is negative by design. If that's your experience, yeah, I wouldn't use an LLM either.

Pretty sure most modern slot machines are digital and you could adjust the odds (even to a positive EV) if you change the code.

You're being unfaithful to the original statement. The whole point of saying something is like a slot machine is that there are significant odds that you lose. If you ever have access to a casino slot machine that has a positive EV, there are no tangible negative aspects anymore; you would use it over and over again and accumulate significant wealth from the house. That's my point.