You do have a point.
I would still recommend to just restart the PC after a quarantine and deletion of any unwanted malware etc.
In today's fashion, its not really that time consuming. But it might feel like an unnecessary process / step. Tho I think its a limbo between the system itself, and the program. It's a process that is needed. I might be wrong.
Thinking about it, it would be a possibility to make it like you imagine. But again, system memory etc, maybe the outcome is different from system to system. ( Laptop, Desktop etc.)
I just do the restart to make sure, and be relieved of the even thinking about, "is my problem gone?!"