

As a long-term Nova user, my biggest problem with replacing it is finding anything that provides similar capabilities. There were reasons why it was so popular for so long. That probably also limited the market for launchers with a similar approach. I can only hope that its decline will cause someone to build something similar.
Of the available options, Lawnchair seems to be the best, but that doesn’t make it a good option. It probably does three-quarters of what I rely on in Nova. That isn’t actually a complaint about Lawnchair. It wasn’t intended to be a Nova replacement… It’s a good launcher in its own right and I really appreciate that it is also FOSS.
I guess my point is that people keep saying there are lots of alternatives to Nova. Yes, there are, but there are currently no substitutes.
My only addition to what Meron35 said is that Launchers can provide interfaces that both look and act differently than the built-in launcher. Some of them are radically different from the default, with everything from expanding radial menus to an actual command line. There is not single best solution that suits everyone, so Launchers allow you to decide what experience works best for you.