High Value Ceramic Chip Capacitors Out of Spec

When I was a teen, I would never have considered a ceramic capacitor when I needed, say, 5 μF or more.  That automatically meant using an electrolytic capacitor, or in some cases, solid Tantalum.  But today, I can buy surface mount capacitors in 4.7 μF, 10 μF, even 100μF.

But wait.  When I actually got those capacitors in hand and measured them, they seemed to be lower in value than marked.  A capacitor has tolerance; I get that.  But if it has a -20% tolerance specified, I expect it to be at least 80% of the marked value.  The ones I got were way off.

10 μF reads low
Marked value: 10 uF. Measured: 7.09 uF.  Brand new from Mouser.
22 μF cap is low.  Measured: μF.
These were also brand new.  Marked value: 22 uF. Measured: 11.76 uF. It seems that the only thing sure is that a 22 uF cap will have more capacity than something marked at the next lower value in the series, 10 uF in this case.
Marked value: 10 μF.  Measured: μF.
Marked value: 22 uF. Measured: 9.36 uF.  I got these at a flea market – maybe they were previously rejected as out-of-spec?
ok 10 uF
Marked value: 10 uF. Measured: 9.05 uF.  Okay, within 10%.
ok 2.2 μF.
Marked value: 2.2 uF. Measured: 2.03 uF.  No problem here, but this was a relatively small value capacitor. I noticed in general that capacitors of 1 uF and less, even bypass caps, seemed to accurate.
100 μF cap is way off
I got this whole strip of caps at a flea market fora dollar. 100 uF in a 1210 package!  They measured only 58 uF, unfortunately.

I’m wondering if there is some kind of scandal about to break here, as the actual capacitances are so low in some cases. It’s like buying a dozen eggs in the market, and finding out that there are only 7 in the box. Perhaps the capacitors are marked in terms of “equivalent filtering capacity” compared to aluminum electrolytics? It is somewhat true that a lower value ceramic can often be used, due to lower equivalent series resistance (ESR). But like audio amplifier power ratings or battery mAH ratings, I still see it as basically lying. Heaven forbid someone needs to use one of these as a timing element.

Component SPEC Reading VERDICT
 Murata GRM31CR61H106KA12L  10 μF X5R 10%, 50V, 1206  7.09 μF  FAIL
 TDK C3225Y5V1C226Z  22 μF Y5V -20+80%, 16V, 1210  11.76 μF  FAIL
 Taiyo Yuden LMK235F226ZN-T  22 μF, 10V, 1210  9.36 μF  FAIL
 TDK C3225X5R1A106K  10 μF X5R 10%, 10V, 1210  9.05 μF  PASS
 TDK C3216X5R1E225K  2.2 μF X5R 10%, 25V, 1206  2.03 μF  PASS
 Unknown  100 μF X5R, 6.3V, 1210  58 μF  FAIL
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