Now they demand internet accounts to use the features of the keyboard and mouse that I purchased.

What are you talking about? Which keyboard, which mouse, which features, and which “internet accounts” are they requiring?

Also, Logitech still distributes the older software and it still works for the mice that it used to work with. My MX Vertical works with Logitech Options or the new Logi Options+ software, for example.

Did you try using that software with your new peripherals?

You can find the list by device at https://support.logi.com/hc/en-us/articles/360024361233--Software assuming this isn’t from their gaming line or something. In that case, go here instead: https://support.logi.com/hc/en-us/categories/360001764393-Gaming

Not only that, have to use wide-open-to-snooping Chrome to adjust the settings. You cannot adjust/use your mouse and keyboard if you just use Firefox.

I highly doubt that the mouse and keyboard cannot be used without Chrome.

Due to security concerns, Firefox did not implement the WebSerial API that’s most likely used to configure your mouse locally. Chrome did. It’s therefore completely reasonable that you would not be able to configure your mouse from Firefox.

That API is also supported by Edge and probably by most Chromium-based browsers, like Brave, the “Ungoogled Chromium,” etc… If you have one installed and it doesn’t work, you can probably change your user agent to trick it into thinking you’re running Chrome as a workaround. Most likely they only tested with Chrome and therefore only say they support Chrome, but don’t actually use any Chrome-exclusive functionality.

This only makes sense if they are planning (or are already) tracking my every move online to sell to advertisers or spooks.

That’s a bit of a leap.

If you use Firefox for browsing and only use this Chrome to run this tool to configure your keyboard and mouse, then even with cross-site cookies and so on unblocked, none of that will be visible from the other browser. So this makes you more isolated, not less. Having it in a browser app instead of a desktop app gives you more protection, not less.

If a company can provide a browser app to do everything a desktop app could, then they can speed up development without having to use something like Electron to distribute their app. And there’s even less friction than Electron because their don’t have to check for updates / require users to install the latest version manually, because they can just always serve the most recent one from the site. As a user, you can probably install the tool locally if you want (it’s likely a PWA) but you don’t have to, meaning you get less software installed on (or worse, constantly running in the background) on your machine.