Or you can use a French keyboard layout, type ` followed by a to get à, same with â, ä, or ç. É has its own key, since it’s more common and the only letter that uses the acute accent. No more complicated than key combinations, and easier hand positions than 3-key combinations, really.
Can do it with the compose key if you’re on *nix, and here’s an implementation for Windows.
<compose> + e + ^ = ê, and <compose> + shift + E + " = Ë, etc.
You can also use compose key on any distro (from my experience) with KDE Plasma or GNOME
Or you can use a French keyboard layout, type ` followed by a to get à, same with â, ä, or ç. É has its own key, since it’s more common and the only letter that uses the acute accent. No more complicated than key combinations, and easier hand positions than 3-key combinations, really.