I should ask, as everyone else seems to have a different opinion from mine as to what your actual question is… “What is the question you need an answer to”?.. because you didn’t actually ask one.
I agree on efflorescence. What I disagree on is the reason for the efflorescence. I would also like to see a ‘close up’ of the affected area. Looks like the concrete is pitted from here, thus my not offering an opinion as to cause. I’m not there to perform a thorough review of contributing conditions.