I completely agree, and this has been my main headscratcher since we first heard about a possible anti-trust case.
For starters, I still think things like banks, telecom, and probably oil, and defense industry companies probably need to be broken up, and that they should be much higher priorities. To say nothing of the obscure industries we wouldn't normally think of (Luxxotica with glasses) that are monopolized. There's probably others for obscure things I'm not even thinking of.
And even within tech, I wouldn't even rank Google ahead of Amazon, and I'm not 100% that I would rank them ahead of Facebook either.
And, if that's not all, I think Google at least serves as a check on the other Frightful Five, and subtracting Google will serve to further consolidate tech. And if that's not enough, I feel that the tech industry has served as a useful check against other entrenched industries. Their clash with cable, and occasional work to protect an open internet are a healthy counterbalance to voices of other monopolized industries.