This pseudo-centroid is easy to compute, and it "reasonable" for most countries. But it can be quite far from any sort of "geographic" centroid. Algeria is easy to understand:
The pseudo-centroid for Algeria (country code DZ), for example, (lat: 35.6, lng: 3.24) is about 75 miles (120 km) from the Mediterranian, yet the country is about 1200 mi / 2000 km from north to south. The issue is that most cities are very near the coast, not scattered around the Sahara. So, the pseudo-centroid found from city lat-lngs is skewed far to the north.
A similar problem happens with cities that have annexed a lot of green space. Or counties with all their cites on a river; etc.
I looked for, but failed to find, a country where the pseudo-centroid was clearly in another country. For the curved country of Viet Nam, it almost lands in Laos. Several countries (eg, New Zealand) have it land off the coast; but I decided that does not really count.