I have to agree with you .... I will rather prefer a slim version of Electrum with all the basic features you need... than a feature rich version of Electrum with bells&whistles you almost never use. (Make those add-ons for the people who wants to use it) 

As you said in your post.... loads of features increase attack vectors for more exploits and that is not what we want. Now you have a feature rich wallet with a lot of holes and weak security. (This will also force regular updates and fixes and newer version of the software.. that will open up opportunities for hackers to exploit that too) - Solarwinds hack was done via an update ==>  "install the malicious code into a new batch of software distributed by SolarWinds as an update or patch." Source : https://www.techtarget.com/whatis/feature/SolarWinds-hack-explained-Everything-you-need-to-know