@44: Labels are basically another name for folders, only a message can have multiple labels, and this has more or less been the case in Gmail since the very beginning, even in Basic HTML view.
That said, the default visibility settings for system labels are kind of whack in Gmail Standard View, emphasizing much of the bullshit Google is pushing and hiding many of the ones you'd expect to find. That said, if you go into the labels tab in Gmail settings, you can change the visibility settings for system labels(the choices are show, show if unread, and hide). I went through to make it show inbox, sent, all mail, spam, and trash, and to hide snooze, starred, important, social, forums, updates, promotions, and most of the other system labels that didn't exist in Basic HTML. I think drafts was the only thing I set to show if unread.
The labels tab under Settings is also where you can create user defined labels.
Also, worth noting that while visible labels will have links, these links aren't in the tab ordering of page elements, at least in Firefox 123/124 on Debian using Orca. That said, there are useful headings to get to labels quickly.
From the inbox(or the message list for any other label), I go into browse mode and use the 2 on my number row to jump between the level 2 HTML headings. The first is search(personally useless, the second is system labels, the third and fourth are my user defined labels, and the fifth is conversations(also personally useless). Once on the appropriate labels heading, I press k to jump between the links to individual labels, and the context menu to open them in new tabs(since for some reason, using the usual open in new tab keyboard shortcut makes Gmail open in current tab). Still miss inbox and spam turning into level 3 headings when there are unread messages and would prefer to tab through the links instead of using k, a navigational hotkey I rarely use amuwjere else on the web, but I've gotten use to this.
For navigating the message list, I use x to navigate by checkboxes, the context menu to do actions on individual mconversations, and if I want to do batch processing, I x to the checkbox of the first message, press space to select it, which forces me into focus mode, and once in focus mode, I arrow up and down through the messages, using x to toggle selected/unselected, and once done selecting, I arrow to a selected message and pick the thing I want to do to all from the context menu. Would still prefer to just x through all the check boxes without being forced into focus mode or at least being able to toggle selection with space instead of having the weird key/action combo, but I'm getting used to it... and the context menu having mark read and move to(combining the archive and add label actions in one) is actually an improvement to mark read being buried in a combobox where it is easier to just open emails you want marked read without actually reading them and having to add a label and archive a message in two separate actions.
My outstanding complaints about standard view would include:
Having to find and click the reply link instead of just being able to jump to the quick reply text box.
Not being able to tell what the default reply address for a conversation is.
There seemingly being no way of deleting individual messages in a conversation.
Contacts being buried in the other Google Apps menu... and contacts is a whole other kettle of rotten fish, as when I first found out how to access my contacts from standard view, I momentarily thought most of my contacts had been deleted in the Gmailocalypse as most don't show up in all contacts, but only other contacts, and I haven't even gotten around to fighting to clean up that mess.
There apparently being no way of knowing how many messages there are in a given label without manually counting or going to the label tab in settings(and there, it only lists counts for user defined labels) Granted, I have conversations per page set to 100, and before the Gmailocalypse, I only had about 75 conversations in all maill(and I could cut that number by more than half if Gmail had a merge conversations function, so no idea if multiple pages of messages will make "1-100 of 101" or similar show up).
The aforementioned use of broken editable comboboxes for to/cc/bcc fields when writing an e-mail. Makes me glad that I'm rarely the one to initiate a conversation and rarely forward things.
Having to batch open messages in new windows instead of new tabs. Also, had to uncheck site preferences in Firefox's clear history dialog because opening messages in a new window requires an exception to Firefox's pop-up blocker, and with site preferences checked, I had to redo the exception everytime I cleared history. It also means the recently closed windows submenu is now a constant presence in my history menu when I'm used to it not being there 90% of the time when I go to reopen tabs I want back. This is probably the biggest outstanding annoyance since I have to deal with it constantly... plus links opened get opened back in the main window and opening a link forces focus back to the main window, so if there are ten links in an e-mail I want to open, that's 20 window switches... Plus switching to a window other than the one I just came from is a major pain since my window manager/desktop environment doesn't let me hold down alt and tab through windows one at a time until I hear the title of the window I want, if I want a window other than the one I just came from, I have to hold down alt, press tab twice or more, and hope I land in the right place. It's giving me flashbacks to the Internet Explorer days before Firefox introduced me to tabbed browsing, but worse since I was a sighted mouse user in those days and could just click on the window I wanted on the taskbar... Seriously, forget thedisregard for accessibility and forcing users to adapt to whatever BS the devs want to force down everyone's throats, this is a regression to a way of doing things that went out of fashion over 20 years ago.