Delightful or delighting?

English as a Second Language English Vocabulary, Grammar and Idioms
1

I came across a sentence(taken from a dictionary):

‘I had a delightful holiday’.

Here can i use “delighting” instead of “delightful”?
Is the word “delighting” commonly used compared to “delightful”?

2

You cannot replace ‘delightful’ with ‘delighting’.

‘Delighting’ is usually used with ‘in’:
They were delighting in each others’ company = They were enjoying each others’ company.

3

But both words are adjectives, so why is more common delightful than delighting?

4

delightful = enjoyable
delighting = enjoying

Delighting is not an adjective.