Look - you have hosting. He with a probability of 10 times a year can fail (banal - reboot).
Now you also have a third-party cloud. There's a 10 or 10 times a year chance of it crashing (trivial - reboot).
Then you decide to load jquery with cdn - this lib has a probability of 10 times a year to fall off.
Then you put a metric and a pixel - they are 10 times a year (each) likely to fall off.
You have google rekapcha - it was blocked by roskomnadzor in 2019 - as a result, the site didn't quite work that way.
You have VK comments - but politicians in other countries (Ukraine, for example) have blocked it. And you may not find out about it promptly.
You put a third-party plugin (uLogin for example) - it leaks your visitors and earns on them by uploading malware from a third party to your site. As an example, it leaked form data.
Bottom line - by splitting everything into different solutions you only increase the chances that the end user will experience problems with your site. You don't know how the policies of different countries will block all these separate entities or when the cloud or cdn will have a failure. And that's there. It happens. All you end up doing is increasing the options and chances of failures. Do you need that?
Well, the answer is to keep everything in house. A good hosting service will hold everything.