We just did an IKEA tabletop with 4 screw-on legs.
This let us swap out different-sized tabletops and the various storage options (underneath and on the desktop) as their needs changed over the years. Kid is in college now, and over time this system proved to be cheap, sturdy, and flexible. They’ve even reused the pegboard with little boxes and hooks for office supplies over their dorm desk.
Middle school required a larger surface and more paper management, because their magnet program involved a lot of research projects and was heavily paper-based. But high school had far more reading and the actual work was more computer-centric, so they preferred to have a smaller work surface that would give them enough room to add for a comfortable chair for reading.