Imagine a relatively big wallet with tens of thousands of addresses and 3x transactions.
Now, let's say I restore such a wallet and do full re-scan in two applications - in Bitcoin Core and in Electrum.
Ignoring the size of the blockchain itself when it comes to Bitcoin Core, and comparing only the file size of the wallet file(s), what difference should I expect between Bitcoin Core and Electrum, or, more generally, between Bitcoin Core and other wallet client software that uses json/other textual format to store the wallet data?