Hosting is where white-label work usually falls apart. You ship the site, collect the invoice, and eighteen months later you are the one whose client’s certificate expired on a Saturday — for a project that stopped being profitable a year ago.
For $35 per month per site, billed to you rather than to your client, I keep it running.
It is optional. If you would rather host it yourself, I hand over the code and the deploy and walk away — you own it either way. Most agencies take it, because the alternative is quietly becoming a hosting company that also does marketing.