I don't have strong feelings about Electron, but 50MB more memory for the same functionality does seem like a lot. If every app I have open on my machine suddenly used 50MB more memory, it would be a noticeable hit.
But it is not the same functionality at all. In terms of privacy and security, the older versions do not come close. And we reworked many pain points in 1Password 7 — better lock screen, improved sidebar, new watchtower, item editing, (in)security questions, fully encrypted item icons, item location bar, tag autocompletion, special handling of the scenario where 1Password becomes locked in the middle of the editing session — and I am not even listing 10% of all the improvements here.
Note that that's 50MB more when the 1Password window is open. When it's running in the background it actively uses less memory than it did before. And that effectively means 99% of the time it's running faster than it did