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

GRS

• NBXplorer headers height: 5404563
• The node is synchronized (Height: 5404563)

LTC

• NBXplorer headers height: 2818641
• The node is synchronized (Height: 2818641)
• NBXplorer is synchronizing... (Height: 2537721)

BTC

• NBXplorer headers height: 877083
• The node is synchronized (Height: 877083)

BTG

• NBXplorer headers height: 875851
• The node is synchronized (Height: 875851)

MONA

• NBXplorer headers height: 3539097
• The node is synchronized (Height: 3539097)

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.