While I appreciate the conscious size-saving effort, I need to ask: is 30 MB difference that big of a deal for desktop applications nowadays? A random Electron app that I download will easily take up hundreds of MBs disk space.

That's the wrong question, IMO. The right question is, "Does it need to be that big?" The answer is "No."

Things that are too big are usually composed of smaller things that are also too big.

The proper question is: what's the cost of it being that big? Is it acceptable? Is it worth making it smaller?

I personally don’t think it’s acceptable and the disregard for files sizes generally extends to disregard for RAM usage which is even more unacceptable. Sadly I don’t really have a choice regarding using most of these apps.