If there's a QB there they think worth the pick they absolutely need to make that pick.
That was true of Mac at 15, even though it didn't work out, and it will be true of Williams, Maye, or someone else they think is the real deal at #3.
You can get top-tier WRs in FA or via trade - the opportunities come up.
You rarely see that with a QB and QB is by far the most important player on the field. By far. That's always been true, of course, but the rule changes and the protections offered to QBs have separate the QBs even more from the rest of the pack.