According to @arehmandev who introduced this change in another PR the motivaitons are:
the main one being that phuslu/log actually recreates a log file and symlinks it on each command run (traversing logs becomes tricky as you have to go into multiple files), not consolidated single log file, easy to lose history
The 2nd was just uber/zap is a community endorsed package
Just some decent support with lumberjack.v2 for log rotation - size, backups, compression etc
Uses a new logger.