What is the syntax difference between "most" and "all" in this context_

Consider the following two sentences:

1a) I eat dinner at home all of the time.
1b) I eat dinner at home most of the time.

Both of these sentences would be viewed as grammatically correct by native speakers. In the case of 1a, 'of' can be elided and have the meaning remain the same. However the same cannot be said of 1b, as illustrated below.

2a) I eat dinner at home all the time.
2b) *I eat dinner at home most the time.

I'm curious to see the syntactic reason behind why the 'of' in the most-expression cannot be elided. I look forward to your feedback.

Solution 1:

of is a preposition which is used to express the relationship between a part and a whole.

As all denotes nothing is left behind, the usage of of is unnecessary.

But most is something which is not the whole, of is always needed to express the relationship.

Examples:
Most of you are eligible.
All of you are eligible (or) All are eligible.