Well. I've already mentioned several times in other threads, that there have been genealogists in Europe centuries before the U.S. were barely a concept.
In France, to speak only of a country I know well, every family has her/his genealogist, and a tree somewhere in a drawer. Online, you find ancestors of about anyone on Geneanet, which is the tool used by 99,9% (it seems) of French people putting their tree on-line. Not to mention other online data bases focused on French aristocracy, such as Roglo or Capedia.
Remind you that genealogy was not a hobby for noble families under the Ancien Régime, but a way to prove nobility, and you needed to seriously document several generations.
Add to this that birth, marriage and death official recording has been mandatory in France since the 16th century, and that all those often very well kept records are available online through public free interfaces, managed by municipal or regional Archives. So, if your ancestors are mostly French, you don't need any US-based resource whatsoever. I for one never ever use Ancestry or unameit-based-in-Utah.
So I would say that the interest in genealogy is at least as strong, and with no doubt more ancient here in France (again, would not speak for other European countries I don't know well) than on the other side of the pond.
Again, I've invited since I've been collaborating to WikiTree, many cousins, close or n-times removed, having impressive trees on Geneanet, fruit of thousands of hours, years of work. But all arguments to bring them in have been killed by the "American" look and feel. Not only the English-only interface, of course it's an issue, but the global feeling of all the thing. For example the challenges, badges and so-on. French genealogists are deadly serious - too much, certainly, and that kind of folklore is as far as possible of what could attract them. I suspect even the too kind greeters messages to be counter-productive, felt as too intrusive re. privacy.
Add the naming conventions, and the inherent complexity of WikiTree editing acknowledged by anyone, even the American-English native speakers, and you have added too many hurdles.
Some of my French cousins have accepted to register, happy to be connected to The Tree, but their activity afterwards has been next to nothing. Some have offered to help me in the back-office, so to speak, finding sources etc, but will let me do the actual job of adding profiles and editing.