Why there are many guest accounts?

Why there are many guest accounts?

After I saw this answer, I realized that there are many guest accounts on
my system:
cat /etc/passwd | grep guest
guest-jzXeRx:x:117:127:Guest,,,:/tmp/guest-jzXeRx:/bin/false
guest-l5dAPU:x:118:128:Guest,,,:/tmp/guest-l5dAPU:/bin/false
guest-FdSAkw:x:119:129:Guest,,,:/tmp/guest-FdSAkw:/bin/false
guest-eBU0cU:x:121:131:Guest,,,:/tmp/guest-eBU0cU:/bin/false
Moreover, in this moment there is nobody logged as guest, but if somebody
will login as guest, a new guest account is created - why, since there are
already other guest accounts?
After the new guest will log out, his account will be deleted. But why the
other guest accounts remain? For what use/purpose?