some ideas

[andreik6v]

1. Rebuild Dashicons (or Ionicons) with only the 4 icons needed (search, menu, close, arrow) and dequeue Dashicons from frontend and enqueue the new lighter icon font. I did this on a child theme, and it weighs 2.5 KB instead of 28.5 KB (Dashicons) or 100 KB (Ionicons).
   Or, use SVGs or plain CSS (https://sridharkatakam.com/css-sub-menu-toggles-in-genesis/), probably will be less than 1 KB.

2. Vanilla Javascript instead of jQuery. I have no experience with JS but what do we need it for? As far as I know, the responsive menu can be done with pure CSS, and other small code could be vanilla Javascript (maybe, I don't know). This way, the jQuery and jQuery Migrate doesn't load, so that's another 40 KB saved.

3. In the Genesis options, maybe have an option to not show excerpt at all (like here - https://demo.fasterwp.com/toki/).

4. Header search (https://sridharkatakam.com/add-expandable-search-icon-navigation-infinity-pro/)

Some of these ideas I have implemented already in a child theme - https://github.com/fasterwp/toki

I am not a developer, I just put together pieces of code, so maybe better implementations are possible from people who know more than me.