E.g. the increase of parlamentarism at the expense of monarchies or other strong heads of state may be a long trend towards this. But I don't think it's a given that such trend necessarily continues. For example kings used to be voted in many parts of the world until 10th century or so, but there was a strong move towards hereditary or other non-elected monarchy afterwards. Similar ebb and flow were seen in e.g. ancient Greece.

https://en.wikipedia.org/wiki/Elective_monarchy