Planck Length – Concept vs Implications

The concept of the Planck length can be fully understood on the basis of only a bit of dimensional analysis applied to the apparent fundamental constants of c, h, and G (whose existences had all been identified long before black holes and even photons were considered to be “real”). It’s implications are by no means yet fully understood, but it is obvious that they will have something to do with the relationship between quantum and gravitational phenomena – perhaps (but not necessarily) as a limit on the possible “sizes” of black holes and/or the wavelengths of “photons”.

Source: (1001) Alan Cooper’s answer to The concept of the Planck length cannot be fully understood without a deep understanding of black holes and photons. So, how did this misconception, that Planck length presented by Planck with vague evidence in his papers written years before that? – Quora