Every time someone mentions a check engine light, I think of the gif above.
What would the problem be, Betty?
For me, I have scanners I can plug into the ALDL or OBD port and get the trouble codes. I can look those codes up in my service manual.
I can also look them up on the internet for a less specific diagnosis.
But idiot lights are kind of like being informed of a fire by the fire department pulling up.
There's many cases where a gauge is far better.
But people don't want to learn about cars and be distracted by little needles. They don't want to learn that different models and engines will put the needle in a different place.
An alarming number of gauges aren't even labeled in any kind of unit.
Sure, you can see if it's giving a higher, or lower, reading than normal, but... What's the range?
Owner's manuals used to tell you what normal was, in units and you'd apply that knowledge to your instruments.
Worse are the ungraduated gauges that lock onto a single spot and only move in a situation where an idiot light would be lit. The 94-96 B-Body has an oil pressure gauge like that. It basically reads pressure/no pressure and is useless for telling how much pressure.
The temperature gauge in The Beast is like this. It will creep up from the bottom until it gets to a given spot and won't move for a nearly 20°C range. If it's overheating, that out of range causes it to, suddenly, hit the top stop. Too late to save the motor most of the time and since it's not slowy creeping up no warning that things have started to go wrong.
I do prefer actual gauges, but the automakers don't give them to me.
And it's the driver who wouldn't understand what they're looking at anyway that caused them to disappear from the dash. Which is most of y'all.