Experience from irregular customer (hobby and education) is that Mouser has not been so bad here in Europe. At least not yet. Haven't used Digikey much because it meant dealing with customs. Haven't checked lately if this has been changed. I've worked professionally with Arrow and it has been nightmare. China just isn't worth of effort – dubious quality with long shipping times. But probably most of the time I've used Farnell (https://www.farnell.com/) and it has been good enough for me.