I agree with Erik on this one and I've been pretty high on Saric, but Butler is clearly a top 20 player and is arguably a top 10 player. Those guys just don't grow on trees. They are hard to get and if you can get one for 2 rotational players and a 2nd round pick (plus getting back an injured but recent near lottery 1st round pick), you have to make that trade every single day without a second of hesitation.
And I get that Butler is 29, but he has only played in 471 regular season games (about 15500 minutes), plus another 43 in the post season (1600 minutes). For a point of comparison, those are about the same amount of games and minutes as Irving and this board doesn't seem to have any issue with giving Irving a 5 year max (and Irving has a worse injury history). And they are way less then Horford's mileage when Boston gave him a max contract and less then Hayward as well (well not the post season for him, but he played in way more regular season games and minutes then Butler has to this point though maybe by the end of the year they will be comparable).