Can we get resource usage of pod without metric server? If yes how? And how accurate is it compared to the kubectl top command

Question

Basically I want to know if we can get resource usage values without using metrics server and if yes how.(Values obtained should be approx. same as obtained by kubectl top command)

I tried getting resource usage by entering into the pod using "exec -it" and checking the cgroup using: cat /sys/fs/cgroup/memory/memory.usage_in_bytes cat /sys/fs/cgroup/cpu/cpuacct.usage

But I dont know if they are the same as we get when we use kubectl top command?