Your node is synching the entire blockchain and validating the consensus rules...

GRS

• NBXplorer headers height: 5515096
• The node is synchronized (Height: 5515096)

LTC

• NBXplorer headers height: 2865547
• The node is synchronized (Height: 2865547)
• NBXplorer is synchronizing... (Height: 2537721)

BTC

• NBXplorer headers height: 888747
• The node is synchronized (Height: 888747)

BTG

• NBXplorer headers height: 887347
• The node is synchronized (Height: 887347)

MONA

• NBXplorer headers height: 3612765
• The node is synchronized (Height: 3612765)

DASH

• NBXplorer headers height: 1874916
• Node headers height: 1874916
• Validated blocks: 1874916

Watch this video to understand the importance of blockchain synchronization.

If you really don't want to synch and you are familiar with the command line, check FastSync.