That's, like, your opinion, man.
Also, you genuinely don't have a clue what you're talking about. 2D spritework requires a lot less work, and in particular doesn't run into the issue 3D modeling has of requiring multiple experienced specialists to produce art that's functional (never mind looking good). It makes physics easier, it reduces the entry cost for the artwork if the dev doesn't already have the programs they need, it's easier to preview and iterate art since you don't need to run it in engine, and on and on.
What all of that means is that far less time gets spent on art, which means more man-hours for design, coding, and QA testing. For a small-team project spritework is objectively the superior choice because it's more economical, easier to make it look good, and frees up more time for the really important considerations. That's why so many indie games are 2D. As one more kicker, it makes modding far easier. It's all the same considerations as making a game in ASCII except you don't have to worry about plebs crying about not being able to understand the visuals.
A game like this with 3D movement and models would not get made in the first place by a solo dev or small team because of the expertise and time required. Relic wasn't just Garden and Moloney when they made Homeworld, they were a full studio with a dedicated art department, and the dev time for just a linear campaign and a few multiplayer maps took more than two years. Their core leadership was 4x the size of the entire dev team for Starsector, they were working on a game with much smaller scope, and they still took several years to build it with a complete studio.
If Alex was trying to make 3D Starsector we'd probably still be on a single star system with twenty ship models, there would be almost no modding community, and we'd be lucky to have that. Look at 3D space games today, all the modern ones that don't have a massive budget and studio behind them are either almost identical to what we had twenty years ago or have almost no content because the time and money was spend on decent 3D models.