How so, everybody gets to enter in and learn / study at the same StarFleet Academy.On the contrary, your proposed "no divide" is fundamently and intrinistically far more elitist and divise than the streamlined "single track, two entry points" system that Starfleet has been shown as having no later than mid-TNG.
But what is the degree in, not everybody is going down the "Tactical" or "Command" route.Because if you insist that "everyone is a commissioned officer" ie an Ensign or above, then only those who have schooling, connections, intelligence and mindset to spend four years on degree level schooling are allowed to be part of Starfleet, everyone else is excluded because they "aren't good enough".
Trade Skills and speciality is very welcomed.
Hell I went to a trade schoool of sorts and I'm very happy with it.
That's fine, that's what StarFleet Academy should be, a flexible University that has a "Common Course" needed for the basics of a StarFleet Officer without going through too much details in management / command. All the basics needed to be ½ Military Officer & ½ Scientific Explorer in a specialty trade of some sort. Doesn't really matter if you're a Scientist, Doctor, Engineer, Pilot, Combat Specialist, etc. There is room for everybody with every trade skill on a StarShip or StarBase.On the other hand, Starfleet -- recognising that practical, non-academic types can be useful if you play to their strengths, allows said people to initially take shorter more focused courses that lead to a specific role, then implicitly gives them if they wish to expand on their qualifications and get promotion to the managerial officer ranks in time. In fact, dialogue from Flashback seems to suggest that a motivated "Specialist" can actually gain promotion all the way to Ensign quicker via that route than the Academy (We don't know when Janice went for officer training, but she specifically tells Tuvok that she completed it in three years, rather than the four or more that new entry candidates spend there)
Let the Students figure out what speciality are they going to start with and have a wide common General Education requirement to establish the basics so that they are ready for space travel, travel amongst fellow alien cadets, and onto alien planets, etc.
Then everybody can focus on what they need to do. We saw alot of that in Lower Decks where they all try out each department until they fit into the department along with the career path that they want to progress on.