[openknot]

>All these things bring a lot of complexity without any real meaningful gain..

This assertion doesn't contradict the author's claim that no language is overall more complex than another. The usefulness of the complexity isn't part of the argument.

>At the opposite a language like Esperanto is really easy to learn..

Esperanto is a constructed/invented language, deliberately created to reduce complexity. It's implied that the author was comparing the complexity of different languages that evolved naturally.

[dwohnitmok]

Moreover the implied consequence of the "equal complexity" thesis is that over time, were Esperanto to be more widely used as a mother tongue for a large population, it too would collect additional complexity as certain stylistic choices would start hardening into first idiomatic and non-idiomatic language patterns and then further into new grammatical and phonological rules.

[renox]

I'm not so sure: now we have academies which tries to codify language changes..