As a suggestion for an initial step, it would be very helpful if a future version of Construct 3 added a direct export option for Capacitor. At a minimum, this option could generate a basic capacitor.config.json file. For the rest of the process, such as building the app, users could then proceed locally/manually.
I highly agree, I think this solution is easier than fully supporting Capacitor (hence doable by Construct team) while also gives something to the advanced users. Win-win.