Yes, it doesn't really make sense that you MUST stop formula exactly on the dot of their first birthday. It's not like an internal switch goes off and previous to this they need formula and after they don't.
FWIW I have read a bit about the history of formula and it used to be that they would advise giving formula until 6 months old and then it was unnecessary and could be replaced with cow's milk. This was at a time when the recommended weaning age was around 3-4 months, and so by 6 months the baby's diet was majority solid foods (this is why the older generation are so obsessed with you getting to 3 meals a day really quickly). So really, the shift from formula to cow's milk is about the shift when the baby is more reliant on their calorie intake from food than they are from milk. My experience with breastfeeding (my own, and being in various support groups and training as a peer supporter) is that this shift can happen a little bit later with breastfeeding, some time during the second year as opposed to during the first. The advice when I had DS1 (15 years ago) was that they should be on mostly food by 9 months old. For my younger two children (2 and 5) I got the sense that the advice is now 12 months roughly for that shift. So I would say to use that as a rough rule of thumb - once the baby is on majority food and milk is a minor part of the diet, it's sufficient to switch to cow's milk, formula is no longer necessary (breastmilk/breastfeeding continues to be beneficial as long as you + baby want to). That will be different ages for different babies but probably somewhere around 12 months or possibly shortly before. During the formula shortage in the US last year, they were advising anyone with a baby older than 9/10 months who was taking on a lot of solids to switch to cow's milk in order to free up supplies for those with younger babies who really needed it.
Interestingly, this is also how follow on milk for the 6-12 month marketing slot is conceived as well - it's meant to be designed for babies who are taking in majority food and aren't as reliant on the nutritional additives in formula. I feel this is not well communicated at all - most people assume it is basically the same as first formula.
Formula is not technically an alternative to breastmilk or a replacement for breastmilk - it's more of a replacement/alternative to the other things that people used to feed babies on, which were very crude by our modern standards - unpasteurised animal milks, flour and water, broths, strange mixtures involving orange juice and cod liver oil. People have the perception that it is an alternative to breastmilk or a synthetic version of breastmilk or based on breastmilk because, again, marketing suggests this but that is not really what it is - it's just a complete food suitable for infants who are not yet eating a varied solid diet. Research on breastmilk has influenced some of the additives and nutritional make up, but it's not where it started out. It does the job it is trying to do very well, it is a totally safe option, and is a million times better than those old options so there is no reason to look down upon it, but it is a completely different thing to breastmilk all the same. Some people will take that as an implicit criticism but I don't think it is, it's possible to say that one thing isn't the same as another while accepting that both options are perfectly valid with pros and cons which will appeal differently to different women/families.