Most 100 Mbps service in the US is cable, so asymmetric. But I think fiber is the only widely deployed technology that can give you 100 Mbps symmetric. Fiber coverage in Switzerland is about 30%:
https://ec.europa.eu/newsroom/document.cfm?doc_id=47090 (see page 30). So if most households can get 100 Mbps, it’s probably not symmetric, but asymmetric VDSL2 or cable.