But pgbackrest exactly helped with that. With compression and parallel process in backup, the backup and restore was quick. I used this, where I took a backup and immediately did a restore so less wals to replay, else wal replay is indeed slow.
Thank you, people. The big problem in my case, which I have not mentioned, is that I think the network is a bottleneck, because I am running pg_basebackup through internet from local country to Amazon instance in Germany and the speed in copying is around 50 MB/sec max, that is why it takes 2 days for copying.
I will try using high compression for the basebackup to reduce the time.
