BBEdit's indenting and completion engines just aren't as smart as other editors -- I suspect in the latter case they'll have to add LSP support on their own (right now I don't think it can even be added externally because their API doesn't expose the right event hooks), and in the former case, I have a suspicion Bare Bones Software just has a philosophical objection to context-aware indenting. With those objections aside, BBEdit is still pretty good for development.

For the technical writing, I actually wrote a comment here somewhere about that in another post; I'll have to dig it up and turn it into a blog post at some point. But I called it a "fast Swiss army knife for text." Its "open file by name via fuzzy searching" command lets you enter multiple files, its multi-file search window lets you save file filters with meaningful names (and you can save grep patterns the same way, and in BBEdit 13 there's even a "Pattern Playground" that lets you nondestructively test out complex regexes on your current document). Projects get their own persistent scratchpads and Unix worksheets. And, a bit relevant to an Emacs thread, BBEdit has a bit of Emacs-ish keybinding support over and what Mac editors normally do, although it's decidedly not an Emacs emulation layer.