In the D&D5E Player’s Handbook, the Paladin’s description states that they
“learned to draw on divine magic and cast spells as a cleric does.”
The cleric is capable of ritual casting, and thus it would seem as though the paladin should be capable of ritual casting. Paladins pick domains from the same options that clerics get, and only the Paladin’s spellcasting information lists only the differences between the it and the cleric class. According to specific beats general, it would seem that a Paladin should be capable of ritual casting unless it is explicitly mentioned to not be the case.
There is a sage advice where Jeremy Crawford answers a question about whether the ranger can ritual cast, but the answer was that rangers lack the ritual casting class feature. Here’s where we get to the part where I disagree with applying that logic to paladins. According to the class description for rangers,
The ranger harnesses the power of nature to cast spells much as a druid does.
In my interpretation, “much as a druid does” is different than “as a druid” because the “much as” implies there is not complete overlap in the way the two classes practice magic. So why is the general consensus that Paladins can’t ritual cast without taking a feat to do so?