I cant see any reason for it … maybe you can give me an explanation.
Money
You don’t for all mp games.
Back in 2022, Xbox changed its Xbox Live Gold membership to no longer apply to free-to-play games. That means over 100 titles are now truly free and don’t require a paid subscription to play them. You will still need a free Xbox Live account but don’t have to pay for Gold membership.
Other than that, servers cost money to keep online
You implement that Servers for Consoles cost more than for PC 
?
I know that Free2Play Titles are also Free2Play for Multiplayer (excluded Destiny 2 MP)
But the question is still why you have to pay for consoles MP and for PC not. Btw. most games using modern Engines they work via P2P or Dedicated - in both cases only 1x masterserver needed with monthy costs around 10$. (or take a look onto Unity Engine Server solution or Steam Service … Epic Games Server integration)