I found Dominik's list of reasons for using brackets incomplete / one-sided.

I would include at least the two following positive reasons.

1. While brackets may disrupt the flow for readers who are not also looking at the Sanskrit, they are helpful for those who are comparing your translation with the Sanskrit.  (Since translations of most Sanskrit philosophical texts, especially the more technical ones, are extremely difficult to understand without simultaneously looking at the Sanskrit, I find the use of brackets in the translation of philosophical texts more desirable than undesirable.)

2. Intellectual honesty.  Use of brackets signals what follows straightforwardly from the Sanskrit, and what is the result of addition or interpretation on your part – which English etc. words correspond to Sanskrit words, and what you have chosen to add in to complete the sense, to disambiguate, or to make explicit to the reader what would have remained obscure if you had just stuck to rendering the Sanskrit words.

Best

Alex