Separation and hands were a concern. Those are quite important.
I’m not surprised he didn’t go in the first several rounds, but I figured a few teams would take a chance late. His blocking and size alone should have justified that. With a good QB and OC, Lazard is very valuable.
The only thing I recall hearing about him was speed, which he proved otherwise at the combine. There is no such thing as separation in the NFL, it's more a matter of catching balls that may be contested and he had miles of tape showing that ability.