Activating venv environments is a bit of a ****shoot, if you're been
getting clever or cute with your PATH. I don't recommend using it.
Instead, urge using this:
pip3 install ansible-core --user
Note the use of the "--user" option, which puts things fairly
consistently in $HOME/.local and as part of your default PATH. No
additional "activate" step needed.
Also, don't install ansible. Only install ansible-core, and install
modules from 'ansible collections' only if and as needed. Your setup
will be *much, much, much* smaller and more stable, because the
updates of individual and non-backwards compatible modules from the
ansible collection is an unpredictable hazard if you install the
"ansible" suite of more than 100 distinct modules written by many
quite independent companies nad developers.