To start off, Firefox. This also applies to Chromium and Firefox forks. It's all the same.
If I want to reduce my usage of Firefox, what services/tools do I genuinely need firefox for? What am I not willing (or unable) to give up?
Besides these services, I'd be interested to see how far I can go in making EWW my primary way of interacting with the web. It'd be nice to create my own interfaces to services and sites I use regularly. It's not all that great at filling in form fields in EWW, but couldn't I do a lot with completing-read or crafting up tabulated interfaces etc. Emacs has a bunch of ways to create text based UI. We should use that way more often!
Negatives of using EWW include frequently getting hit by Anubis and not being able to get around that, along with not being able to see personal websites custom CSS. This might seem like a minor thing but I absolutely love seeing personal expression. What aesthetic does a person have, what kind of website do they want me to see? It's important, and with EWW you lose that. Of course, you usually only care to see the presentation of someone's site once or twice. The novelty wears off, it becomes a background in your mind, you automatically know how to navigate it, and then just like that you're no longer able to actually see it.
So, I could occasionally use Firefox for that. But this 'occasional' can quickly turn back to 'regular'.
Next up, general purpose search engines. I want to write more about this but for now I'll just say: the advent of LLMs and their destruction of the usefulness of general purpose search has largely decentivized me from using them at all these days. Unlike many others, I haven't gone the route of using an LLM Chat interface as a replacement of it (what a sick joke), but rather have looked at what kind of searching I usually do:
There's not actually a compelling reason for general purpose search anymore. There's usually a direct resource I'm interested in searching from, so I don't need a Google search replacement.
See also https://search.technomancy.us/why
More to write on this, so much more. And with better focus. Better writing.
In general, I wish more of the software I interacted with on a daily basis was either written by me. Or, at the very least if it suddenly started behaving in a way I didn't like or was suddenly abandoned, it wouldn't change much for me: I would be confident in my ability to maintain and modify it myself. Apart from my site builder, the only tool coming close to that is Emacs. A lot of the stuff on this list is unrealistic to have my own versions of.
Emacs packages I can do.
A window manager I can do.
A fediverse client I can do.
An application launcher/menu I can do.
Bookmark management I can do.
Password management I can do.