Archaeologist here. We have good evidence throughout the past that people did understand the concept of love but as it’s an abstract feeling we cannot truly prove or disprove that any given person in a couple truly feels love for their partner.
In societies with class systems, whether they acted on love and how they acted on it was determined by the social conventions of their society. So for example someone born to a politically important family would quite often seek a match that put their offspring in a similar or higher position. But it is called a match for a reason- if the relationship did not work from the outset it wouldn’t be made official (unless one of the parents was really bloodyminded). That doesn’t necessarily mean the partners were in love but it doesn’t mean they weren’t, either. If you look at the way royal matches were made, the vast majority of royals had multiple potential matches and chose the one they best liked. If all upper class individuals were pushed into loveless arranged marriages with no personal agency, we wouldn’t have famous examples like Elizabeth I or Jane Austen who were lifelong spinsters- we wouldn’t have the word spinster!
The concept of matrimony itself hasn’t been consistent across all cultures/times. The working classes/serf classes etc have generally been more able to partner up with someone they loved but this wasn’t a given. Some cultures had arranged marriages and some just let most people get on with things. The main reason in the recent past that people would have been pushed into marrying someone they didn’t really love would be if there was an unwedded pregnancy. The alternative was a mother and baby home so most women were more willing to marry someone they didn’t love. On both sides of my family, there have been coerced weddings like this - one in the 1940s and one in the 1970s (that one was Irish), and one aunt who got put in a mother and baby home because the bloke wouldn’t marry her. It is easy for us to think the whole of the past was like this but it wasn’t, that’s the fallacy of projecting what we know or remember about the more recent past onto the more distant past.
Christianity has a lot to answer for in this regard. The ancient Hellenic cultures had a very different view of love and marriage (and sexuality), but fidelity was still very important (in the way that they understood it). It would be a mistake for us to assume that one voice from a specific period of time was necessarily fully representative of every individual from that time. But if love as a concept didn’t exist then it makes no sense that we have so much literature about it. In fact it is the central theme of most secular fiction throughout time!
I always thought Odysseus did love Penelope, in the book he slays all the suitors. He wasn’t faffing around on his way back to her - the gods literally decided to fuck with him and throw as many obstacles as possible in his way to stop him. The only reason he made it back was because Pallas Athene (sometimes called Athena) was on his side. More evidence that he loved his whole family a lot - he pretended to be insane to avoid going to the Trojan wars in the first place because his wife had a newborn and he wanted to support her, but got caught out when they threw his baby in front of a plough he was dicking around with and he proved he was sane by saving the baby. He could have just decided fuck it and made another baby if he didn’t love his wife and son. So I believe Odysseus was supposed to be depicted as loving Penelope but that this wasn’t necessarily expressed the way we express it nowadays with all the kissing etc.
I haven’t seen the film but if there’s lots of sickly kissy hand holding that’s a modern depiction to show a modern audience what can be inferred from the text.