I don’t get it. Do you expect him to work for free just because others do? If Boost for Lemmy was completely a paid app instead of free with ads, it wouldn’t see as much adoption. That’s how Sync, Boost and Relay (for Reddit) used to work.
As someone who uses nnn (occasionally lf) all the time, terminal file managers make navigation (especially bookmarking) easier.
Think Nemo’s my default file manager but with GUI file managers I find it hard to switch contexts. I always used to have two splits open with Nemo but if I need to open a new context I’d have to open another instance of Nemo and then I gotta switch between the instances now.
Now, nnn gives me 4 contexts, which can be easily switched between using 1-4. I’ve added zoxide within nnn to pretty much jump to any directory within my system. This isn’t really possible with a GUI file manager. Guess you can add integration to other tools as well to the list of pros of a terminal file manager.
File preview needs a mention as well. It’s easier when you can quickly glance a file and move on instead of opening it.