Not exactly. I don't think it was "too bright", I was just saying it could be a little dimmer and still totally fine. Also, by over-driving, I'd suggest current. It takes both, but you control an led with current and let it take as much voltage as it needs for said current. This type of circuit is generally kept very simple: LED, resistor, switch: for each segment. The order doesn't really matter and the switch is digitally controlled (and some kind of small transistor or mux gate either passing or not passing the current, not a mechanical switch actually making and breaking contact). So you send a signal, "switch" closes, current passes, light comes out (because the pixies are angry as one of my favorite youtubers Ave likes to say). This happens for each segment, but they're generally tied to a single voltage supply. These aren't super specific LEDs, they'd have a max current rating. So you'd know your source voltage, subtract the estimated forward voltage of the LED, divide by the current you're trying to put through the LED and that would give the resistor value for each one. I don't know what the specific current rating is for each segment, but say for example it's 15mA. If the LED turns on around 1mA (just another example), you can pick a current anywhere between 1 and 15, the more current the brighter. So let's just say they picked 10mA, that should be fine forever and maybe meets whatever brightness specification they wanted.
So when I say they may have driven them too hard I imagine a few scenarios.
1: some engineer says "this is the simplest part of the whole circuit, but it lights up, pretty", glances at the spec sheet because they don't want to spend a ton of time on the simple stuff, thinks it's a 15mA part, picks a resistor for 10mA, but buys the 10mA model indicator. They're running right at max current, and sometimes, if the board is warm and runs for a while, they start failing. Woops. Didn't mean to, but accidents happen.
2: indicator the engineer wants is 15mA, resistor designed in sets ~10mA, when boards go to get made, the indicators are out of stock. Months have passed since the design. Somewhere in the alternate part selection process either the wrong indicator is ordered (but looks correct) or the wrong part number is on the bill of materials for a typo, or the distributor puts the wrong parts in the bag and nobody notices. (I have seen this sort of thing happen, and pretty much every electronic part I try to order these days is in stock when I put it on the schematic and out of stock when we go to order it so last minute substitutions are happening all over the place).
3: counterfeit parts do exist and sometimes make their way into distribution. One place I worked got a whole reel of about 1000 power mosfets that were counterfeit. They worked... For a few minutes...then they didn't. Idk how it's profitable to spend the time tooling up fabrication of components that look and sometimes perform almost as good as the real ones, but it happens. I think it's pretty rare that the parts get into the field, but it can happen.
4: More simple: there's a manufacturing defect in the indicators, but no human mistakes were made. Everybody thought it was fine and it usually is, but if you have enough tolerances and circumstances pile in one direction, you get some latent failures.
5: ESD will do that to an LED sometimes. Seems fine, lights up, but what you can't see is the internal stress that was created that will cause a part to die early. So if there was some unseen ESD event on a tray of indicators...trouble can occur. Most manufacturers are super strict about ESD protocols for this reason.
6: sure, voltage regulation problem. Say there's a specific regulator driving these and somehow the 3.7VDC regulator gets bought instead of the 3.3 (for whatever similar reason as above). Now there's more voltage across the resistor, more current in the LED, eventually fails. Voltage regulation could be a DC-to-DC chip or simple as a zener with a capacitor holding a specific voltage; maybe one of those is just a little bad for some reason...like I said, "simple circuit" lol. Nothing is really simple when you build a lot of them.
So, "too much" just indicating that the segments/LEDs couldn't do what was asked of them anymore, but could be for a great number of reasons, plenty of which could basically fall to "luck" one way or another and not negligence. Also could be negligence lol, no idea. When I said possibly the design is bad, I mean that either someone made a mistake, or something got built wrong making the design not work. I would be absolutely shocked if someone who knows how to make the rest of the actually complex circuits work didn't know how to do the simple math above. I would be less shocked if a wrong or bad part was accidentally bought, unknowingly received, or damaged somewhere along the way.
At the end of the day, sometimes hardware fails. I'm not happy about it, but I'm not going to call anybody out or anything. I like a problem to solve, but I wasn't looking for a blame game. I don't know where blame lies and I have no reasonable way or reason to find out. I'm sure they'll take care of it, I just like trying to figure things out sometimes.
Edit: I wrote this on my phone. Please excuse grammar, abbreviations, and typos lol