I've been self-hosting my own websites for over a decade, and while the hug-death of the "slashdot effect" can be real, it is a statistical anomoly and a absurd as a rationale against self-hosting. It is actually cheaper ($ wise) to self-host with equipment you already have. Certs are $0 with LE, everything else is just setting up systems (websites) on equipment you already run and pay for. It is a lie to say that that's somehow more expensive than $14/mo.

If someone chooses to pay for hosting elsewhere, that's one thing, but don't sell the lie that it's cheaper. It's not.

As for the 100k/day unique traffic, that depends on the website served. If it's a fully static site and your setup is tuned, yeah you can actually handle that.