Ask HN: Is it viable to set up a clients website by using free frameworks?

I have been building websites for years now and I almost always wrote them myself from ground up, in order to have maximum performance and control (and for customization). Now it exhausts me though. I work months for simple shops and if it wasn't for the pure enjoyment of writing everything myself, I would have already stopped.

I recently started to think about doing the complete opposite. Using some free (property licensed) framework, free themes and just making minimal changes in order to fit the clients design preferences. For stuff like an event management engine with app and calender integration, I used to work for weeks and now it feels like it's just a click away. Especially toolkits like WordPress/WooCommerce seem like drag and drop programming.

I feel like this is cheating though because it doesn't have anything to do with web development and I would feel like ripping off clients.

How do people normally approach setting up customer projects? Especially if you are trying to make it profitable. I always wonder how those people who live off of "building websites" do it.