I agree 100% with everything you wrote. It was very surprising to me that every transaction and every write operation blocks the whole database and not only the table it's performed upon (it makes sense since it's all a single file, but still).
The only workaround for this is splitting your main database into multiple databases, but this bleeds into your application logic and gets messy quickly. If you are in this position, it's best to switch to Postgres as you did!
The only workaround for this is splitting your main database into multiple databases, but this bleeds into your application logic and gets messy quickly. If you are in this position, it's best to switch to Postgres as you did!