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

GRS

• NBXplorer headers height: 5532203
• The node is synchronized (Height: 5532203)

LTC

• NBXplorer headers height: 2872773
• The node is synchronized (Height: 2872773)
• NBXplorer is synchronizing... (Height: 2537721)

BTC

• NBXplorer headers height: 890613
• The node is synchronized (Height: 890613)

BTG

• NBXplorer headers height: 889119
• The node is synchronized (Height: 889119)

MONA

• NBXplorer headers height: 3624158
• The node is synchronized (Height: 3624158)

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.