These are indeed all valid points that have to be considered when choosing between service and self-hosting.
One point to add is the GDPR. To date, Disqus has not offered a data processing agreement - neither to the public nor on individual inquiry. If I have no DPA until the 25th I have to disable comments on my blog. Self-hosting is additional effort but it also means less dependency on others.
But yes, self-hosting also has drawbacks. Choosing the right option should be done carefully.