The % of people who get jobs doesn't matter. Those people are not you. Maybe the 70% decided they didn't like coding after all. Or maybe the course was crap. Who knows?
You have a good point but I have to disagree with you when you say that "The % of people who get jobs doesn't matter." It does matter. I'm sure you'd agree if it were 1% and not 70%.
It doesn't matter if you aren't looking for a career in that field.
If you are choosing between fields or are looking to increase your income, how many people got good-paying, permanent jobs is highly important. It is also important if you are spending money that might be better invested in something else (such as a reliable vehicle or a down payment on a house if you live in the Midwest).
If you simply want the learning, the money isn't an issue ,and/or you don't actually care to land a job with the knowledge, then the job thing isn't an issue. All depends on perspective and desired outcomes.
Then you need to assess more deeply than % employed because you don't know how motivated they where. For example a ReactJS course could increase your chance of getting a job from 60 to 80% due to your motivation, but only 30% of that class got a job because most of them are just course hopping looking for a career change.