I really like Steve Waugh as a bowler. Heck, I consider him to be potentially the "GOAT" of part time bowlers when it came to quality. But I would still have to say that comparing his bowling quality to Kallis's is a joke.
Kalis wasn't used as a workhorse bowler, like Sobers, he was used as a partnership breaker, and he was good at that role, in my opinion. He was shielded a bit in terms of work-rate yes, but there are obvious reasons for that. Still a player who bowled as much as him can't be protected as much as is implied, and he bowled in the same conditions and struggled through whatever a 4th/5th bowler generally struggles through (set batsmen, no new ball, etc).
And despite the need for protection due to his role, South Africa still made it a point to bowl him almost every innings that they took the field. They felt it was very important to give him that, even if it didn't always match up with his ideal use cases. In fact, he didn't rack up many DNBs at all, until about the last two years of career 2012-2013 where that rate increased.
This is a far cry from the way that someone like Steve Waugh was used, for the bulk of his own career.