There are also advantages for the user. For example, new features arrive for all platforms at the same time; there is no prioritization of platforms or such. Same for bugs - apart from issues stemming from Electron itself, they're likely to appear on all platforms and therefore likelier to get fixed.

In essence, the old "only X% of our users use platform Y, it's not worth it to make this feature/fix this bug for them" does not exist anymore with something like Electron, and while this is ultimately also a cost consideration, it does come with benefits for me as a user, especially if I'm on a minority platform.