None. No "Email service" (let's say newsletters specifically, because obviously gmail exists) has a strong brand - that's my point, it was a blank canvas to start and they've spent a ton on paint with little to show for it.
> Why would an email platform for business be a household name any more than would the top HR software?
Businesses are made up of people. Look at Salesforce, Workday, Zoom...
Let's say you tried that. At best, you'd have a company similar to 2021 Mailchimp at some point in the future (when Mailchimp will be even bigger). So in some sense you'd still end up behind versus buying Mailchimp.
Then you'd have to compete against Mailchimp and other established brands to get there, which means high competitive and execution risk factors. That means your $10B investment in NewMailCo is at risk of loss, with (say) odds of 50% of building a success like Mailchimp. Further, you run the very real risk of losing all of it if you try to start from scratch. Most startups fail, regardless of available capital (Quibi, Juicero, etc.).
The parent comment said “less than that” not the same amount - clearly it wouldn’t make sense if you expected to spend the same. (That said, the parent comment is classic HN “that seems easy” and is likely to be wrong.)