What most toggles actually remove
Look at what's actually inside each platform's toggle list, and the pattern is specific, not blanket. YouTube: hide the Shorts shelf, make Home open Subscriptions, hide the suggested-videos rail. Instagram: block Reels, hide Explore, hide Stories, hide suggested and sponsored posts, default the feed to Following. Facebook: hide Reels, hide Stories. Reddit: switch to Following sorted by New, hide ads. Each of those targets one named feature. None of them touch search, messages, comments, or the accounts you actually follow.
That's not a smaller version of blocking the app. It's a different kind of fix aimed at a different problem: not "I opened this app," but "this specific feature is what keeps me here longer than I meant to be."
Why the full block exists too
Every platform also has a block-the-whole-site toggle. Facebook and Reddit kept theirs as the only option for a while, because neither platform split cleanly into a distinct recommendation feature worth targeting on its own. That's no longer true: both now expose the same kind of named-feature toggles the other platforms have. The full block didn't go away, it just stopped being the sole option anywhere. It's there for the times a feature-level fix doesn't go far enough, without being the assumption baked into the product.
Why blocking everything usually doesn't hold
The problem with an all-or-nothing blocker isn't that it's too strict. It's that it removes the same things you actually wanted alongside the things you didn't, a message from a friend along with the Explore grid, a subscription video along with Shorts. That combination is exactly what makes a total block easy to abandon within a week: the cost of staying blocked and the cost of the thing you're missing get bundled together, and eventually the thing you're missing wins.
Splitting the fix by feature keeps that from happening. The reasons you'd open the app still work. The reasons it kept you longer than planned don't.
The user's call either way
None of this means feature-level toggles are the correct choice and full blocks are a fallback. Some people want Facebook gone entirely and have no interest in a partial fix. That's what the block toggle is for, stated plainly as an option, not the default DoomOff assumes you want. Every toggle, block or feature-level, comes with a live preview before you turn it on, so the choice is made looking at the actual result, not a description of one.