That's fine if you reject the OSI's definition. We've been having this conversation as a community for decades and "the source code is freely available" is not enough.
For instance, there's Debian's[0] (which was considered authoritative enough that the OSI basically used it as their own) which spells out the freedoms necessary for software to be considered Open Source. This extends beyond the source being available to not discriminating against people groups, allowing for modification, etc.
There's another from the FSF/GNU projects[1] which lay out the Four Essential Freedoms. These extend beyond source availability to the ability to run the program as you wish, to study the program and to redistribute it (among others).
To say source availability == Open Source is to rewrite history. It's about user freedom and always has been.
[0]: https://www.debian.org/social_contract
[1]: https://www.gnu.org/philosophy/free-sw.en.html