Setup difficulty depends mostly on whether your building is already wired. If fibre or cable is live in the building, activation can be quick, sometimes just a router shipped to you for self-install. If a technician visit or new line installation is needed, expect a wait ranging from a few days to a few weeks depending on the country and season, which is why many expats bridge the gap with a 4G or 5G router or generous mobile hotspot plan.
The paperwork is the underrated hurdle for newcomers: providers commonly require a local ID or residence permit, proof of address, and a local bank account for direct debit, which creates a chicken-and-egg problem in your first weeks. Some providers accept passports and prepayment, so ask around in expat groups for which ones are foreigner-friendly in your country.
Customer support quality varies from excellent app-based service to notorious call-centre purgatory, and support in English is common in some markets and rare in others. Before choosing, check whether the provider offers support in a language you speak, and favour providers with physical shops if you expect to need face-to-face help.