How to delete smart mailboxes... completely?

Ok so how do I hide them? See attached screen shot of the Smart Mailboxes I'm referring to. Extremely annoying to me as I never use them and they take up so much of my email sidebar. There's got to be a way to remove or hide all of these.

Here's the full sidebar from Mail App. All Inboxes are at the top. Smart mailboxes (useless to me) are below as shown in screen capture. I deleted all the items inside one of them, trying desperately to get rid of these, and all the emails disappeared from the corresponding real mailbox "inbox" above. I thought for sure there would be a way to hide or delete these super annoying so-called "smart mailboxes" in grey. Also shown in my screen capture. I mean there are 100's of tweaks and hidden features and more coming every day... but apparently there's no way to get rid of these grey "smart" mailboxes. I do not understand them, I do not use them, I do not want them taking up space in my sidebar.

Below the "on my mac" section are only 2 items... Drafts and Trash. Below "smart mailboxes" is Today with a gear symbol.

Below that is all the Greyed Out Account Names. Why are they greyed out? I have always assumed they are the Smart Mailboxes... I only ever use the Mail Accounts shown under "Favorites" since they are in Black Type and at the Top, and therefore always visible no matter how collapsed I have the Mail window.

In the screen shot below, I have collapsed the "favorites - All Inboxes" area for sake of space saving in this example. You can clearly see type in solid black. The other greyed out items below Favorites are Smart Mailboxes, On My Mac, and then my email account names (I have blurred them but you can see that they are grey) I just do not understand why they are greyed out and why they are at the bottom if they are the actual mailboxes. If they are teh Real Email Accounts, then why is there not also a "heading" with a carrot that says "email accounts"... My original problem with all this is that I have a lot of email accounts and all the grey names below are repetitive and taking up way too much space in my sidebar... how to hide them or get rid of them. I'm beginning to believe that this is not changeable and that mail app is not laid out in a very user friendly way at least not for me. And I don't think I will ever stumble upon the reason or purpose for "on my mac"... I mean isn't all of this on my mac? Some find it intuitive, I do not :(

Is there a preference in Mail that will get rid of the Smart Mailboxes? I an unable to delete them by selecting or clicking on them because they are greyed-out. The expansion triangle shows "inbox, junk, trash, sent, etc" all of these can be independently deleted except "inbox". Surely there is a way to delete all a particular account's smart mailboxes.

I selected the items (inbox, trash, sent, etc) in the greyed out smart mailbox area for one account and right-clicked "delete" and all the email from the actual account is now gone as well. Everything I have read about this says deleting smart mailbox items will not delete the original message in the actual accounts. What the heck happened here and how do I get my emails back?

Time Machine backs up every night but there are no email messages in the corresponding mail files in Time Machine.

The above links do not do what the articles say they do. I am unable to delete "inbox" but by selecting multiple mailboxes (inbox, sent, trash, draft, etc) I am able to delete all of them and then the actual emails from the actual accounts (the real mailbox) are also deleted!!! Makes no sense. Now I am trying to restore from Time Machine and that is not cooperating either. :(

Ok, I'll clarify... the "smart Mailboxes" I'm referring to are the greyed out ones in the side bar below the Heading "Smart Mailboxes" and below the heading "On My Mac". There is a main greyed out mailbox for each of my 12 Email Accounts. All of them have a triangle expansion icon which, when expanded, shows "Inbox, Drafts, Sent, Junk, Trash" . I have them all collapsed so as not to create even more clutter than already in the sidebar. The problem is Deleting the Smart Mailboxes that contain these other sub-mailboxes. I would like to get rid of the entire area, no more smart mailboxes. I have tried everything and finally succeeded in getting the subs to disappear, but that also deleted all the email in the main account in the uppere area, the normal email area. All this is inside the sidebar. I am now currently copying 125K items (V9 folder in most recent time machine backup) to my desktop so that I can Import to Mail and hopefully restore the lost emails in the one account I used as test for getting rid of the smart mailboxes.

Ok this illustrates the problem perfectly. I use INBOX area at the top, since it's "at the top" and is named INBOX, and it has a triangle expansion icon that shows all my email accounts right up top where they belong. The greyed out items below are noise. They are greyed out. I need to simplify this somehow, one or the other of these areas should be customizable. I've been trying to figure this out for a long time. I just give up and ignore the clutter. I will never understand the layout or functionality. It makes absolutely no sense to me. But Thanks for trying.