GIS and geospatial software is used to capture, store, analyse and publish location data: maps, parcels, networks, assets, routes, imagery and sensor positions. Municipalities, utilities, transport operators, agriculture, defence-adjacent bodies and property companies rely on it for planning, maintenance and emergency response. Esri ArcGIS and Google Maps Platform are widely used non-EU reference points.
The sovereignty angle combines data and dependency. Layers describing pipelines, cables, buildings or vulnerable populations are more sensitive in aggregate than any single record, and movement data about people is personal data. Hosted map services also depend on a vendor's tile, geocoding and routing APIs, so pricing or terms changes can disrupt an application overnight. Open standards partly protect against this: the Open Geospatial Consortium publishes web service and data container standards that different products implement, which lowers the cost of replacing a component.
When choosing a European option, check support for these open standards and common formats, whether you can run the platform on your own infrastructure or in an EU region, and which basemap and geocoding data sources it relies on, including their licences. Look at how role-based access to individual layers works, and whether APIs and exports let you take your geodata with you.