Of course people were counting that!
I recall a Calvin & Hobbes cartoon where Calvin phones up his dad at work and asks him what he's doing. "Don't you think a game of Calvinball would be more fun?" (It would be, of course, so Calvin's dad heads home to play.) Or just think about the cliche of a politician retiring "to spend more time with his/her family."
Your examples sound great and noble but not really very realistic. Realistic is parents checking Facebook and Instagram at otherwise idle moments -- "idle" when they could be paying attention to their kids.
You are probably right that historically, many fathers were absent a lot of the time. That has definitely changed a lot but I don't think smartphones are the cause.
Even if everything you said is correct, there could still be a significant difference between "my dad isn't here a lot of the time" and "my dad ignores me a lot of the time" (smartphones greatly enabling the latter). Neither is great, but the latter in particular risks setting a dangerous example to kids when it comes to them learning how to socialize with others.
Before smartphones, a working father might head after work to the bar, to avoid his own family until he's calmed down from how frustrated his boss makes him. After smartphones, the same father might instead head into his study with a bottle of whiskey and talk to his friends (who are also getting drunk in their own homes) on a group-chat, or over a game of Fortnite.
Before smartphones, a stay-at-home mother might have to run errands for a few hours: going to the bank, going to the grocery, going to attend a continuing-education class; and she would perhaps leave her child at home, or ask someone to babysit them, depending on the age. Now, instead, she's setting up some bill-payments and transfers in a banking app, then picking through a grocery-delivery app, and then watching an online lecture and participating in a forum as part of an online continuing-education program.
In both cases, the parents are now spending more time at home than they were before—but no more (or less) time paying attention to their kids than they were before.
If you measure the delta (time where you're near the kids but ignoring them), it looks like it's going up. But this is as misleading a statistic as the one that says seat-belts increase injuries: no, they don't, they just turn fatalities into injuries, and nobody was counting the injuries sustained during fatalities. Nobody was counting time spent outside the home as time spent ignoring your kids.