The block subsidy is inflationary. The important thing is that the inflation schedule:

1) halts, and

2) is set in stone and cannot be changed

This makes it trivial to show that the bitcoin supply is capped. This gives every bitcoiner confidence that the value of their investment will not erode.

Confidence is sexy. It makes bitcoin more popular. Money is a natural monopoly. The more popular a form of money is, the more useful it is and the more popular it becomes.

Monero makes different tradeoffs for a different use case. It can't win by copying bitcoin's playbook. I think the tail emission is a good idea to keep the miners mining.