I feel like part of why this is a + thread for exactly what people want is to prevent the perennial derail of people telling us we're wrong for not just why we want a better fighter, but for wanting one in the first place.
Well, I'm definitely not telling you that. By all means we need a better fighter. So please don't tell me we need a Warmain or 4e Fighter. By all means pick out aspects of what those attempts did that you think moved the fighter in the right direction. But as soon as you endorse existing design as the fix, when I can pick out a half dozen reasons why the existing attempt failed per the standard of how I defined a "complex fighter" namely, as the OP just said, "most people just want to see more interesting options available to fighters as a core feature of the class, not a subclass trait.", well then I feel the thread is not endorsing a "complex fighter" and has moved to shutting down open discussion and toward the same arguments we always get into about which existing solution was best. To me as soon as I see the fighter has subclasses that do something no other fighter subclass can do, it fails this test. As soon as I make a choice that locks me into something and out of something else, it fails that test.
Let me try to explain the problem by giving an example. In my D&D campaign I had a player come to me with his character concept, "I want to play a character who is a natural TP/TK who is hiding his magic ability and pretending to be a warrior." And I was like, "Cool concept. Here are some options that will enable you to do that." Essentially he wanted to play a Jedi Knight in D&D, inspired in part by the fact that I told him Sorcerers are often hunted down as dangerous inhuman monsters in my campaign world. So imagine for a moment that the option I gave him was a sorcerer subclass "Psychic Warrior" that locked him into a fixed spell list and a set of character abilities all the way out to 20th level. (I didn't, but imagine I did because that's what so many solutions to the fighter are actually like.) Now the guy keeps playing his character to 7th level and at 7th level he decides, "Hmm... you know what, this fun but I need some sort of area of effect attack." And at that level he picked up "Shrapnel Blast". Now this was starting to get outside of his original conception, and probably wouldn't have fit into a subclass for a TP/TK. The player decided he was no longer hiding his abilities from the rest of the party, and was getting comfortable making more visible magic. If spellcasters were made like martial classes, to a large extent this sort of flexibility isn't possible.
What I want is not to pick 'archer' or 'gladiator' or 'warlord' or whatever at 1st level and then that's what I do, it just has some extra toys compared to fighter implementation X hard coded into the build. I want a class design where a player can say, "I'm going to be an archer", and then at 6th level says, "AND, I'm also going to be a swashbuckler" and then at 9th level says, "AND, I'm also going to be a warlord!".