Too many external links?

[aqeelat]

uBlock reported that tanstack.com uses stuff from: (categorization is my own)
Ads:

• carbonads
• doubleclick
  Analytics:
• google-analytics
• mixpanel
• newrelic
• segment.com
• scarf.sh
• googletagmanager
  Functional:
• google fonts
• github
• stackblitz
• neo4j
• orama
  Other:
• reactbricks
• route4me.com
• rxdb.info
• stackblitz.com
• toyokumo.co.jp
• usenextbase.com
• webcontainer.io
• workflowgen.com

I understand the use of some of these resources, but I would like to know more about:

1. why are some of them redundant? it seems like there are 6 tracking/analytics tools. why?
2. why use more than one ad network?
3. what are the services listed under other used for?

I'm curiously trying to learn (not bashing or complaining or anything of the sort). I searched for many of them in the repo and didn't find anything. I assume they might be coming from the hosting provider.