Your claim was that you're not going to "pay for an ad service". If you're proposing to be a paying client, that population of paid clients seems like the most relevant possible population. Yet you're dismissing it. How is a service that displays no ads and collects no data for use for ad targeting an "ad service"?
Is my data processed by a separate service? Are the execs at gmail-for-paid-clients different? Do I have any recourse if they decide to update some policy document like they did in the past in their other business lines?
Frankly, it's just that much easier for me to feel secure when I get that service from people whose main business is email and not advertising.