The media is picking this up more; in the last ten years or so, it's been fairly commonly mentioned in the media.
This article by the Ringer points out that we're seeing poor 4th down decisions about half as often as we were ten years ago; the person they quote mentions "Win Probability Forfeited"1 specifically as the statistic that reduced by half.
The biggest reason, though, for why they don't go for it is that they get attacked in the press the next day, and by the fans, when they go for it and fail. When they do the "normal" thing, not much is made of it, maybe except at the very end of the game; but when they do the aggressive, different thing, and it fails, it is mocked. Look at what happened after the Patriots lost to the Colts in 2009 after going for it on 4th and 2 deep in their own territory with the lead; Bill Belichik, perhaps the most successful coach in history (and certainly of today), was crucified in the press - except by the stat junkies, like myself, who were happy he went for it as going for it was the better WPA choice.
See these responses, from former Patriots:
“The worst coaching decision I have ever seen Bill Belichick make,” former Patriots safety Rodney Harrison said on NBC. For ESPN, former Patriots linebacker Tedy Bruschi said, “As a former defender on that team, I would’ve cared less about the result of that fourth-down attempt. The decision to go for it would be enough to make my blood boil for weeks.”
Yet, it's definitely changing - as the same article notes, teams on 4th and 1 went for it over half the time last year relative to the 2019 date on the article(so in 2018). That's a huge improvement over the rarity that it was ten years before. Coaches that are more aggressive, like Ron Rivera, are given quaint nicknames ("Riverboat Ron") instead of being run out of town.
I would also add that it's much more complicated than "7 vs 3". Unless it's 4th and goal from the 1, you're not getting a touchdown every time; you're getting a first down, and that leads to a touchdown some percentage of the time. The FG is also not an automatic make, of course, either. You have to consider the down and distance, and the location on the field - and the game scenario. 4th and 1 with 15 seconds remaining, up by 6? Let's kick that field goal. 4th and 1 with 3 minutes remaining, from the 40, low shot at making the FG, and only winning by two? Going for it is much more important here (not to mention the "behind" scenarios). The NYT had a Fourth Down Bot for years that used statistics to show what the best choice was, given no information about the time remaining or the score - just the location on the field - which was a good baseline, but needed some consideration of other information. Win Probability Added is the key statistic here, so pay attention to that.
1 Win Probability Forfeited: the difference between Win Probability Added values for going for it versus kicking/punting. If going for it on 4th and 1 will suceed 60% of the time, and if it succeeds the win probability added for the subsequent first down (or scored touchdown) is +30%, but the win probability added for failing is -10%, then your Win Probability Added is .6*.3 + .4*(-.1) = +14%; while kicking the FG has a 80% of adding 3 points, which adds say 16% win probability, and a 20% of failing, with a -12% win probability (it's worse, due to the lost 7 yards!), so (.8*.16 + .2*(-.12)) or around +10% WPA. So the "Win probability forfeited" for attempting that FG is .14 - .10 = 4% Win Probability Added