Native multi-selection is the worst. The fact that you have to hold down a modifier key to make multiple selections is a usability nightmare. I have rarely seen

Native multi-selection is the worst. The fact that you have to hold down a modifier key to make multiple selections is a usability nightmare. I have rarely seen a person who knows how to use the native browser widget. Even when you do know how to use it, it is just too easy to make a mistake. If there were 5 options already selected and you want to add a sixth, so you click it but you forgot to hold down the right key. Now the 5 previously selected options are gone with no way to get them back. In general I like using native widgets because mobile browsers do a lot of work to make native widgets usable on phones, but <select multiple> is so bad on the desktop that I always replace it.