Why can't a developer adapt a site to 100% functionality?

Question

HTML

Good afternoon, dear professionals and website development specialists.
We need reasoned advice on the site and adaptability. The developers and I entered the conflict zone.
The site was developed on html5, without java and other obsolete nonsense.
Here it is - www.granteworld.ru
All the cheese is from behind the main page, in which there are elements of dynamics - a falling grenade, an exploding grenade, an icon on the right to buy online and a grenade goes for texts.
The contract specifies the point of site adaptability for all devices (mobile + tablets + stationary on ios, android, windows, etc.).
The site has been adapted for mobile devices. BUT! missing:
1. the ability to zoom in on the touch screens of the main page (try it)
2. the grenade burst stage is gone
3. grenade rides over texts
4. no icon to buy online
The developer claims that it is impossible to achieve 100% adaptability (exactly with the approved version).
The question is: is it possible or not to achieve this 100% adaptability? if so, what are we sacrificing (for example, a heavy site will turn out).
Thanks in advance for answers, questions, criticism and recommendations.

Answer 1

1. Your site is NOT responsive. It does not adapt to the device on which it is viewed.
2. Sites stuffed with such user interactions are practically not amenable to adaptive layout, because there are different interactions on mobile devices, the performance of mobile devices is different.
3. It is not possible to watch this site on iPhone 4S.
4. On my i5 2500K, the website tab consumes 75% of the CPU.
Conclusion:

Answer 2

You are a typical hostage of the absence of clearly described scenarios. Why do I think so?
1. Why do you want to zoom in on the main page?
2. Why should the user want this?
3. What devices might require this?
4. Why are these devices not provided with a different interface construction, so as not to bother the user with an unnecessary action?
I only asked some of the questions about the scale. And for each of your points you can paint.
Alas, this is the problem with many projects. Yes, there are many - the vast majority.
Hello, do you make websites?
"Of course, what do you need?" Business card site, catalog or promo site?
- Well, I don’t know ... I want cool ...
- The budget of such a site starts from 300,000 rubles.
- Expensive ... But there was not, let's!
- Within an hour, the manager will send you a technical specification and an estimate.

Answer 3

Good afternoon! Unfortunately, I'm not a developer, but just an admin, but due to my profession I often participate in conflicts of misunderstanding with developers.
I'll give you a little advice: give an exact quote from the developer to give the toaster audience a complete picture of the situation, since your current post exposes the developer as very stupid and flat-headed, and he probably had specific arguments, perhaps not unfounded.
Well, he didn’t just answer you, “it won’t work that way,” right?

Answer 4

1. On such sites, there is no need to give the opportunity to enlarge the screen, otherwise the whole idea will be lost, the pomegranate will blur, hell knows how, all the buttons will also float. give the opportunity to change the screen size only when changing the position of the phone / tablet, but not when pinch to zoom
2. pain.
3. tell your programmer about z-
index