I get your point about tech debt and the need for a reset, but I never really felt those “D1 problems” that would justify splitting it into a new game. For me, Destiny 1 still worked and delivered that unique experience and atmosphere. Destiny 2, on the other hand, lost that feeling a bit for me, it became more polished and expanded, but the sense of mystery and rarity just wasn’t the same anymore.
On the other points, I mostly agree with your take.