The answer is simple for low-drop regulators that need capacitor at output for their stability. If you add extra distance between IC and capacitor you are adding inductance in serie with capacitance making IC "don't see" capacitor at its output.
For example a description of Output capacityor from TI:LM1117 datasheet:
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9.2.2.1.3 Output Capacitor
The output capacitor is critical in maintaining regulator stability, and must meet the required conditions for both
minimum amount of capacitance and equivalent series resistance (ESR). The minimum output capacitance
required by the LM1117 is 10 µF, if a tantalum capacitor is used. Any increase of the output capacitance will
merely improve the loop stability and transient response. The ESR of the output capacitor should range between
0.3 Ω to 22 Ω. In the case of the adjustable regulator, when the CADJ is used, a larger output capacitance (22-µF
tantalum) is required.
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Mentioned by you standard regulators don't have stability problems. Even we know this I would use C as specified in datasheet close to regulator.
You can also do some experiments. If you design fast switching load and observe IC output voltage when load changes abruptly you can form an opinion if IC is completely stable or close to instability.
Going the path of 'as specified in datasheet'... In TI:LM317 datasheet you read about output capacitor:
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• CO improves transient response, but is not needed for stability
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So as they write 'not needed' then 'not needed'.