Exactly, as I understood it, flattening the curve doesn't necessarily result in fewer infections, just more spread out so that the total number of sick people at the same time are always less than the number of beds available. The price you pay for this of course is that the virus remains a problem for that much longer, and the economic/social hardships and deaths that come with that. Even all those charts they show to demonstrate flattening the curve. The total area under the curve appears to be about the same.
Unless you're proposing completely eliminating the virus from the world small pox style, super lock down would merely delay everything.
There are really 2 "reasonable" approaches to this - and when I say reasonable, I mean rationally justifiable within a certain set of assumptions:
1) Be like Australia - knock the infections down to a very low level, with the assumption that you can manage cases going forward with contact tracing, etc. - with the end goal being to use this approach to hold out until a vaccine is developed(or it runs its course via herd immunity in the rest of the world). The objective here is to achieve a good public health outcome, but to be able to reopen after the virus is knocked down to a low level that enables it to be controlled through means other than shutdowns.
2) Be like Sweden - assume that the endgame is herd immunity, and figure out how to get there with the fewest deaths and least economic damage along the way.
In both of these cases, there's still benefit to sustainable social distancing (masks, other things that reduce transmission without shutting down businesses), because it can help you achieve effective herd immunity with fewer total infections, and/or allow you to open more things without excess risk of transmission.
The problem is that an intermediate approach gets you the worst of both worlds - lots of infections and deaths, *and* lots of economic damage. In fact, a long, half-baked lockdown with premature reopening probably will cause more economic damage(and be less effective from a public health perspective) than a shorter, harsher lockdown. But this is exactly what we're doing in the USA - half-assing the lockdown and extending it for too long as a result, then reopening before we've really got cases under control. It's a middle ground in a situation where the middle ground is the worst possible approach we could possibly take.