Diminishing returns at some point, but, I think the counterpoint to this is companies who are doing a single huge manual deployment every month (or less) which is scheduled into a 4-hour outage window where many if not all services will be down for this period.

I do agree there isn't a lot of delta between a company doing 2 or 10 deploys a day and a company doing 1,200, but, there's a huge engineering gap between companies who do approximately .03 deploys per day and those doing multiple.

Open source projects can be the worst at this stuff. I realise it's all volunteer run so I'm not complaining too much. But so often they end up pushing a versioned release once a year. So you end up finding a bug, going to report it and see it was fixed 8 months ago but still broken in the published package. And then they get afraid to push a new version because it's been so long since the last one that everything has changed.