ForkLift is for people who move files for a living and have got tired of doing it in one Finder window at a time. Two panes, keyboard-driven, with a remote server treated as just another pane: drag from a local folder into an SFTP connection and it uploads, no separate transfer app involved. It also absorbs several small utilities — folder sync, folder comparison, batch rename with regular expressions, an app uninstaller — which is usually what makes people stop paying for two or three other things.
The licence needs explaining. Twenty dollars does not buy updates forever; it buys the app plus a year of them. After that the copy you have keeps working for as long as macOS lets it, and new versions mean paying again. That is cheaper than it sounds — a year or two between purchases at these prices is well under what a mounting subscription costs — but go in knowing it, because the store page calls it a lifetime licence and people read that as "updates forever".
Skip it if you connect to a server twice a month; Cyberduck is free and fine for that. Skip it too if you want a pure transfer tool rather than a Finder replacement, because most of the price here is the file manager.

