11,000 players online right now where are they?

[♥♥♥♥♥♥♥♥♥♥♥♥]

Are they playing quick match or something?

[sard3379]

Try changing filters in server browser, including slots

[Rogue5642]

Most likely players in different countries. There are a ton of full servers in Japan and Germany in BF1 and BF5

[Mannequin]

Change filter to show full servers. Some servers use bots to fill slots and you won't see it if your filter doesn't show full server.