when I read the creation account as a literal narrative the net result is not a whole lot. I don't need the creation account to know God created the heavens and the earth and the order of it all in a literal vacuum seems obscure and enigmatic. But when I stop forcing a literal narrative as its goal a gospel message of light being spoken into darkness ending in rest emerges that has immeasurable impact. It's not that I'm saying it's not literal, which I'm indifferent to, it's that in practice reading it as a non-literal account is more beneficial and impactful to Christian theology. Believe what you want about its literalness, but don't study it for those reasons, study it as a salvation message.
You could say the creation account is goal-driven to built to the 7th day and cement it in to bolster the 4th commandment and if so then this too is not about the literal, it's about looking at the creation account as building to law (specifically the 4th commandment) which I find to be anti-climatic and counter-gospel. Let's call a spade a spade here, which are we first? Sabbatrians or Christians? Christ is the central message of scripture and however wrong this sounds the sabbath is not the central message as the sabbath can only be defined through Christ. If creation, the 7th day or the 4th commandment cannot point to Christ then we've missed the point so I'm just cutting to the chase and viewing it under the lens of Christ rather then the lens of the Sabbath.
Paul makes a quick comment in 1 Cor 4:6 saying "For God, who said, 'Let light shine out of darkness,' made his light shine in our hearts to give us the light of the knowledge of God’s glory displayed in the face of Christ." not often looked at but Paul here is actually giving us a form of commentary on the creation account conflating the light of creation with the gospel message. This calibrates the account into a salvation context under biblical authority. If the light of day 1 is a gospel/salavtion message what is the dark formless void that the spirit of God overs over? what is the meaning of waters above and below that a new body of land rises out of? What are the seed-bearing plants? What is the sense of filling up the formed bodies of day 1, 2 and 3 with days 4, 5, 6? What is the command to multiply, and then of course when complete what is this rest?
the salvation message in the creation account is light being spoken into a dark formless void which should by no means be controversal. Light into darkness is probably the most used metaphor in the bible so this should be no surprise why it is the first act of creation even to the ruin of logic since the sun is created after the light. Light is the initiating act of creation as it is with salvation so in this context it's clear why light is placed first whereas in a literal vacuum the logic of it doesn't add up. In the account the days goes on forming and organizing, filling and multiplying and when complete ushers in rest. Perhaps Phil 1:6 sums up this account by saying "he who began a good work in you will bring it to completion at the day of Jesus Christ".
"rest" is "sabbath" in the account. it is a verb, not a noun and can be translated as "cease". God of course is perfect in all ways so has no need for rest and any act that is done is done with direct intention. God's work of creation was complete and because it was complete he ceased creating. rest then is a product of a completed work which of course is a parallel to the work of God with us that Phil 1:6 puts attention to. This 2 sided coin of completion and rest adds layers to the meaning of sabbath and builds this message of salvation from light to rest that is missing when we only connect the dots to the 4th commandment. The 4th commandment echos this message but the 7th day does not echo the 4th commandment if that makes sense, the message is the same since the beginning. God sends light, transforms us and gives us rest. What gives us rest? If Christ is the central message of scripture then of course Christ is the central message of the creation account and the central message of the law including the 4th commandment. he is the one who gives us rest.