I feel like paid, targeted ads on platforms everyone uses are extremely insidous, because an incumbent or major political party will always have more funds than an e.g. an upstart party, and targeting is generally bad as it's easy to play into people's preconceived notions that way, instead of presenting your position or the change you advocate for.
Edit: replaced "incumbent" with "incumebt or major political party"
You typically only need a few thousand well placed votes to win an election, and even 100k impressions at $10 CPM is pretty inexpensive.
In the context of the EU this isn't true though, no political system in any EU member state relies on a tiny minority of votes from some states/provinces to completely tip an election.
For example the run off thresholds in French legislative elections. And some places like Italy still use FPTP in a hybrid form.
However you're correct that there's nothing quite like Pennsylvania in the EU.
https://en.wikipedia.org/wiki/2024_French_legislative_electi...
https://en.wikipedia.org/wiki/2022_Italian_general_election#...