FileZilla explicitly and emphatically sells a license, not a download. In fact, technically not even the initial download is included in the purchase. They’re technically within their rights to never even give you the software, just say “all we ever sold you was a promise not to sue”, but we’d all agree that’s a scam, right? So, where’s the line?

Point of comparison, Steam, CodeCanyon, and Gumroad all let you re-download the version you licensed indefinitely.