Anti-trust laws are all written to remedy the situation where a company with dominant market position uses it to gouge the consumers. Google most definitely doesn't do this (search is free, Android is free). Amazon uses its position to drive the prices down. Intervening here would probably have the effect of actually driving the prices up or shutting down of free services. That probably would not play well with the public.
I'm not entirely convinced that break-up is the desired solution to advance competition. Nokia was massively dominant, but still fell with no government intervention. Microsoft used to rule the desktop and browser markets. Got disrupted organically. IBM before them.
Where I see the need for adjustment is the tendency of tech giants to just buy up and absorb potential competitors. And even there, with very careful and deliberated intervention.