Tracing is poor at both very long lived traces, at stream processing, and most tracing implementations are too heavy to run in computationally bound tasks beyond at a very coarse level. Logging is nice in that it has no context, no overhead, is generally very cheap to compose and emit, and with including transaction id and done in a structured way gives you most of what tracing does without all the other baggage.

That said for the spaces where tracing works well, it works unreasonably well.