1. Swift fell apart because its C++ interop was broken and the tooling was immature
“The issue was that Swift’s C++ interop is still half‑baked and kept breaking the build.” – fdefitte
“It looked to me like it was just due to recurring build issues… trying to add swift to the project was breaking too many things.” – guywithahat
2. The language‑choice debate is dominated by Swift vs. Rust vs. C++
“In the end it came down to Swift vs Rust, and Swift is strictly better in OO support and C++ interop.” – mlinksva
“Rust has straightforward support for every part of OOP… but it doesn’t have implementation inheritance.” – antonvs
3. Migrating a huge C++ codebase is a massive, costly undertaking
“Migrating any large project is going to be billions of dollars worth of labor.” – bluGill
“Language isn’t a large factor in the cost of migrating a large project.” – bbkane (questioned)
4. Swift’s Apple‑centric nature and lack of open‑source control are major red flags
“Swift never felt truly open source… Apple still holds all the keys.” – isodev
“The fact that Swift is an Apple baby should indeed be considered a red flag.” – stephc_int13
5. The decision to abandon Swift is seen as a case study in poor engineering management
“It’s a wonderful case study in how not to make engineering management decisions.” – refulgentis
“They decided to abandon Swift because they realized it wasn’t going anywhere.” – incognitojam (commit note)
These five themes capture the core of the discussion: why Swift failed, how language choice matters, the practical realities of large‑scale migration, the influence of corporate control on language viability, and the project‑management lessons learned.