That is still quite a small pool, and there are other network effects preventing any Joe blogs with that much capital from launching an exploitation campaign.
To, once again, use the same example of NSO Group as it is infamous and well-documented [1]. In 2016 it was 500,000 $ upfront and 650,000 $/year for 10 devices. That article claims Saudi Arabia was monitoring 15,000 phones at a average cost of 10,000 $/phone. In [2] it was 7 million $ for 15 devices, but the upfront versus marginal cost per device is not broken down. And this was a relatively "above-board" company in the sense that they were a legitimate business entity with government deals which commands a premium relative to random unknown blackhat organization with no reputation.
And again, my original comment was discussing commercial profit-motivated attackers for which 1 million $ is easily within reach and just a cost of doing business to unlock greater amounts of profit. That is less than the cost of setting up a McDonalds. There is a vast, vast gap spanning factors of millions between Joe Schmo and commercial actors and a even vaster gap to state actors. There is no evidence that Lockdown mode is adequate against even commercial actors, let alone the vastly more capable state actors.
[1] https://prodefence.io/news/pegasus-spyware-operating-costs-c...
[2] https://www.reuters.com/business/media-telecom/meta-suit-aga...