I don't usually make lengthy posts like this but I wanted to give my view on it. My reasons as to why people born in 2010 are not gen alpha are as follows:

Generation alpha is seen as a generation that are tech-savvy and competent with modern day, materializing technology, like artificial intelligence because they were born in the time period in which they proliferated and mainstreamed with society.

We typically get our first memories when we are around the age of 3 - 4 years old, which would be 2013-14 for 2010 borns. This was a time period where the technology that was conventional was mainly traditional CDs, DVD's, CRT TVs, etc.

Generation alpha were born in a time period where these technologies began to fade out with society as more modern technology was becoming more mainstream, and they do not remember a time period with the traditional technology back then, because they get their first memories at a much later time period.

The same thing can be said about smartphones too

Other than IPhone's debut in 2007, smartphones weren't very popular and flip phones/bar phones were the main attraction until more companies started to make more innovative smartphones from 2016-present. Smartphones were obviously still a thing even before 2016 but all these modern technologies like built in assistants weren't really a thing up until about 2016

COVID too

Most if not all of generation alpha will not be able to remember a time in which COVID caused international lock-downs all across the planet because they were only infants/early toddlers back then, which means they will never know a world where COVID wasn't a thing

2010 borns were 9-10 years old when COVID proliferated across the world

They will obviously have a memory of a world where COVID didn't exist because they had first memories over half a decade before COVID had an outbreak

Anything after 2010 I would say is gen alpha, but I think 2010 makes the cut off for gen z

So yeah, that's my take on it, thank you for reading.