Conflicting information about residence permit and freedom of movement act

So I have found conflicting information on google and different websites concerning the Freedom of Movement act/EU and residence permits.

As far as I am aware, as an EU citizen I am under the Freedom of Movement Act/EU.

"All EU citizens and their family members have the right to move and reside freely within the EU."

Which allows me to move and reside freely within the EU for as long as I want without the need for a residence permit.

Also according to the Freedom of Movement Act EU, if an EU citizen gets married to someone who is not from an EU country the Freedom of Movement Act also applies to them. (...and their family members...)

Now the conflicting part, on some websites where marriage is mentioned they say that after the marriage a permit of residence can be requested and that getting married *only* for that wihout actually living together in a marriage union is a sham marriage etc.

So, if the Freedom of Movement Act exists, why is a Residence permit mentioned since the former makes the latter obsolete by the description alone or are the websites where residence permits are still mentioned not updated since 2005 where the freedom of movement act came into being?