Typically on high bypass-ratio engines during the first 3 or 4 seconds the acceleration is mostly in the high-pressure part of the engine with little increase in thrust.
Thanks HazelNuts.....so that lends some credibility to pushing the levers,
thinking nothing is happening, closing them to "try" again etc etc
Could be BS (particularly with the experience level in the flight deck) but I see no other way how the crew could try several times with no response....but TOGA worked, albeit too late.