Why write a website yourself when there are ready-made engines?

Question

CMS

Hello!
I don’t understand anything .. I
watched a lot of lessons like: do-it-yourself CMS, online store from scratch, etc.
All of course interesting and useful.
Completed a couple of orders for fl.
Question
When an order says, for example, "I need an online store", I can do it from scratch with a bunch of some chips, etc. But all this is in any engines.
It turns out that it's expensive to do it yourself - and if you choose an engine, it's generally free.
I had an order to develop a booking system.
Here I did it from scratch - but it is clear to me why this is so.
How then is the work of the developer generally evaluated?

Answer 1

The question is strange:
1) Your developments will eventually turn into a kind of engine, i.e. the time will be almost
equal it is necessary to cut taking into account the architecture of the engine
3) not all and not in any. For example, in the engine, the announcement is made automatically from the first 200 characters of the text, but I want to add it myself in a separate field
4) Expand, adjust the design, tighten it - it will still take about a day in the simplest case if the sites are not a carbon copy
5) He does customization, there can be a lot of problems with the customer's Wishlist
6) In fact, how much the client is willing to pay - this is how much it costs

Answer 2

Firstly, in order to use the engine, you need to know it, at least at the level of design implementation. If everything suits him, then you don’t need to write anything. If the finishing touches are significant, then it may be easier to implement on the framework.

Answer 3

And really why? For serious projects it is better to program in php framework!