In the UK it is very easy to switch providers if you use a BT line. As this is a result of local loop unbundling rules that were in place before Brexit it must be the same within the EU, and other countries may have similar rules.
It is not particularly difficult to switch to providers that have their own local connections if they supply your area either (in the UK, at least).
It is not particularly difficult to switch to providers that have their own local connections if they supply your area either (in the UK, at least).