Converting a Drupal 6 website to Drupal 7

I am now seeing where it asks above the version you are on, and it says Drupal 8.x?? I thought we were all on Drupal 7, Is there a reason my developer is not going from Drupal 6 to Drupal 8? Especailly as it is taking a long time. I was under the impression that code is code. Why does it take a long time to say take a custom theme and copy all the code and logic and then paste it into Drupal 7?

If you have not guessed by now, I am not a developer. Just the guy who is fastly going broke trying to finish a Drupal site that has now taken the better part of 4 long years. I am tired of it and ready to throw the towel in. I thought when a "while" meant 2 weeks, not 3 months to switch over to Drupal 7. Does it erally take a few months to set up a complete new Drupal 7 website from an all custom themed Drupal 6 travel website?

I am thinking of going back to Drupal 6 as that was farther along and then doing this way down the road. Anyone that can give me perspectinve on these frustrations?

What would you guys do that are true Drupal Gods. I am a marketing guy and need this site to go live or I need to can it. How long would it take you guys to put together a travel website from scratch, start to finish with 2 custom themes and a custom homepage. Including a very easy to use back office for someone tech challenged, that would need to use it for changing or ading hotels, articles, etc.?

Absolutely any insight sure would be appreciated and so welcomed. I am at wits end tonight!

Kind Regards, Terry