Team Site or Communication Site? Which one should I choose?

Of course you know the answer, it depends! There are still plenty of things you can't do with Communication Sites without custom web parts so for now, there is a home for all types of sites. I think of publishing sites in the same "class" as Communication Sites but they are much more mature. If you want to delay scheduling of pages, have more control over branding, etc., you will still want to use Publishing Sites today. But, I can definitely see a way to integrate modern Comm Sites into an existing intranet based on the Publishing framework - especially for "fit for purpose" sites like a campaign, initiative, or a governance/training site where it is less important to have the global nav or custom branding. I don't think there is one best way or one right answer here. Every choice should be about the business problem, the user experience, and whether or not you have budget and resources for customization.