Just scrolled around a little bit 2-3minutes with network monitor open. That already resulted in 500requests, 5MB transferred (after filtering by vector tile data). Not sure how many of those got cached by browser with no actual requests, cached by browser exchanging only headers or cached by cloudflare. I am guessing that the typical 10-20 requests/user case is for embedded map fragment like those commonly found in contact page where most users don't scroll at all or at most slightly zoom out to better see rest of city.