Larranaga was on the cusp of being fired after a couple of subpar seasons. He worked with the AD and others to determine what it would take for the program to right the ship and be successful, and his superiors made it clear that they wanted NIL and the transfer portal to be the emphasis. Miami has high profile boosters, so they have lots of money, and a nice environment that young people dig, and rather than reject the portal like some old school coaches, he embraced it.
Because his job was on the line.
Now, turning to lewis, I'm not suggesting he's going to pick miami. But if you're a kid like him, you probably figure that you're going to be a one and done before jumping to the nba, or max 2 years. So you're probably thinking, the weather will be great, there's beautiful women, not a bad place to spend a year or two while I'm getting paid.