For promoted, you'll need to use like a browser extension or something 3rd party to remove those. I would be VERY surprised if they gave native ways like this to mute the main income source of their platform (promoted tweets/ads). haha
They have the "See this less often" option if you click the options chevron within the promoted content. I'm convinced it's a placebo feature but...that's just me.
Yeah, that (placebo), or it could mean "see this less often" of this TYPE of ad. So more about the content than the actual ad. Again, I highly doubt they are just going to let users use the platform without any ads.
My assumption is that is only for the particular ad or company and that they will just show you ads from other places instead. More of a way to nudge the system into showing you more "relevant" promoted tweets than actually removing them.