By culture/routine, MLB is a 6 days a week sport. Economics aside, they just wouldn't consider cutting a season down to 120ish games. And even if they did, that's still 120 games I wouldn't be watching.MLB that's a huge problem, like I get it's a game of fractions of fractions so you just have to have all these attempts to pan out, but every time they say oh such and such team is behind, I'm like what only 134 games left in the season, OH NOOOO.
NBA is similar but they are under 100 games, but they are now trying to fix the "resting starters" nonsense finally, but that was always another knock.
I think that is another reason, besides just the violent nature of the NFL that fans love, short of one team DOMINATING the entire season, every game matters for teams trying to make the playoffs. No team is ever going to sit a healthy starter short of having their seeding locked up.
NBA isn't an everyday game, and the product improves a lot when players get adequate rest between games (compare the cadence of playoffs to regular season scheduling). Ideally they'd pare the regular season back to about 70 games, but nobody wants to lose the revenue.
I didn't grow up as a big football fan, and it's still not my favorite sport. But as you noted, every game has leverage and importance (even if not for playoffs, but for job prospects). This weekend is chock-full of interesting games, even though I'm not invested in the specific teams that are playing.