Do you mean that anyone who has installed Compentents Anywhere on their site is condemned to staying with Joomla! 3, or to completely reconfiguring their site to be able to remove this extension before migrating to Jommla! 4?
Correct. If you want to include a component on your Joomla 4+ website in an area that is not the component itself (like in a module) and it has no module for it itself, you will need to find a different solution.
First step would be to ask the component developers to crate a module that does what you need.
On Joomla 3, it is causing a lot of issues and conflicts with certain 3rd party extensions that I cannot solve on my end. Which in turn creates a lot of support requests which result in frustrated users (and a frustrated me).
On top of that, the sales for it remain very very low.
So it causes me more headaches than pleasure, and the time and energy I have to put into it is not worth the returns.
The extension is open source, so you are more than welcome to ask another developer to port the extension to Joomla 4+, if you so wish (or do that yourself).