it is true that they do not integrate with widgets and theming, but that's not exclusive to electron. GTK apps don't follow system widgets, nor will they follow theming on non-gtk desktops. I do also prefer desktop apps not be written in electron for the performance reasons you mentioned.
I don't really have a YouTube video or blog post on hand to explain it, but I do have a degree in cybersecurity. Putting a malicious executable in a video is not a simple task. The most likely way for this to occur would require a vulnerability in the video player you are using that allows for code execution. If your system is up to date, it's unlikely the video player you're using is going to have a known vulnerability that allows this. If someone does have knowledge of a vulnerability like this that is not publicly known, it's very unlikely random 1337x users will be their target.
Something I will recommend is if you are using Windows, make sure you do not have file extensions hidden in File Explorer, because then someone could trick you by simply naming an executable with .exe at the end. These types of tricks are more important for the average user to be cautious about than attacks utilizing steganography.
Electron is capable of having just as good integration with the system as native applications. It's just that a lot of people are not optimizing these cross platform apps to have optimal integration with them. Electron has the safeStorage API that allows you to use kwallet or GNOME Keyring to securely store information. I believe both Discord and Spotify use this on Linux.
They're not just giving these AI companies your data...
It's an optional feature, and you would choose which model you use. If you choose not to use it, or disable the feature, nobody will recieve your data. If you want a browser without these features, Librewolf will likely be a safe choice, as I don't seem them adding this.
Nix is useful for CLI packages, which aren't very simple to use through flatpak. It also has far more packages, and is very useful for creating development environments.
I mostly play on a Steam Deck, which lets you use it on most games by emulating a mouse. I played through GTA5 and some other shooters with it. On switch, the others I know of are Splatoon 2 and Overwatch 2 (I think)
I believe they work on the main console interface, but the majority of games don't implement support, especially FPS games due to the advantage they offer.
it is true that they do not integrate with widgets and theming, but that's not exclusive to electron. GTK apps don't follow system widgets, nor will they follow theming on non-gtk desktops. I do also prefer desktop apps not be written in electron for the performance reasons you mentioned.