Hello, today I stumbled over the same issue as https://projectdmc.org/support/topic/fatar-error-4/
This issue will happen to anyone running a tad more modern plugins using Composer Dependencies that are not tailored to support outdated PHP versions.
It is your choice to support those PHP versions, but I would kindly want to ask, please do not force anyone else to prefix their Composer Dependencies when they choose to not support those PHP versions.
Instead, you should either prefix your dependencies or update them.
Tools like php-scoper can help you with this. The thing is, if your plugin is installed on a website and anyone uses a newer PSR or else (monolog, etc etc) Dependency, then Fatal errors become the case. In my opinion it is not the task of the developer who choses modern versions to prefix their code. If compatibility is your main concern, I feel the task is on your end.
Thank you!