It's been 5 years since Butler became a rotation a starter.
In the past 5 years:
Butler has played 81% of his total regular season games.
Butler has played 100% of his total playoff games.
For comparison purposes (top teams)
Gordon Hayward has played 74% of his total regular games.
Kyrie Irving has played 80% of his total regular games.
Al Horford has played 79% of his total regular season games.
Kevin Durant has played in 75% of his total regular season games.
Butler isn't a rare case. Most players are around his % of games played. His minutes are concerning, but most contenders will reduce his minutes a lot (especially teams like Toronto or Boston, who have actual NBA benches)