About what?

Anyone who has never even used a computer before can go to one of these websites, follow the instructions on the screen in front of them, and get it done. Zero experience or skills required.

No they don’t. People who have never used a computer before have trouble even using the mouse. They don’t know what a file is, they don’t know what a filetype is, they don’t know that you can convert one type of file to another, they don’t know even to look for a file conversion website, they don’t know how to upload a file to a website, they don’t know how to find a file in the file dialogue, and on and on. Seriously what are you on about?

Overall fair enough I guess. I didn’t say it was simple though, i said it was not more complicated. Your experience using GUIs and web interfaces probably spans years. It’s not like you’re born with GUI skills.

Making a GUI is more work than making a CLI tool. GUIs are not cross-platform, a pure CLI is more portable. You can code a CLI with any programming language you like, while there are many restrictions on what kind of GUI is available on what programming languages and platforms.

The GUI code is tedious and boring to write. That code can become outdated and broken and might need fixing to run on newer platforms. The CLI has essentially no extra dependencies and the interface hasn’t changed much since like the 70s.

The sort of person who develops free software usually knows and likely prefers to use the CLI. They’re not doing it for users like you, first and foremost. They’re doing it themselves, or because they need it for their job. The CLI tool might be exactly what they want, because the file conversion is part of some backend stuff, something that’s run from a script, so you can automatically run it on all the files.

Anybody with basic web dev skills can then take these tools, slap together web fronted and try and make some quick bucks. They’re basically incentivized to not care about security, privacy or anything like that. Of course that space attracts scammers.

The incentives just aren’t there for it to be any other way. You can either learn the CLI commands, written by people who care about their reputations and professional pride and want to share their tools. Or you can trust anonymous internet randos wanting to make a quick buck. And while I sympathize not wanting to have to learn new shit, I swear using a shell isn’t actually more complicated than using a web browser, you’re just not used to it.