You've been given an alternative lunar lander, one that's lighter and safer, why does it not get the job done?
...because a couple of chairs and a frame would appear to provide little in the way of storage for tools, supplies, return of lunar samples, navigation equipment, etc etc.
You appear to be proposing, assuming the retention of a command and service module, that two astronauts would don suits, exit the CSM, get into their "2 seats and a frame" by unspecifed means in order to descend to the surface, and would then use this frame to return to the CSM, where they would enter the CSM by unspecified means. Would you have an airlock on the CSM? Wouldn't this increase its weight? Have you considered how this would impact other aspects, such as fuel requirements, re-entry, etc.?
You're providing a vague, sketchy description, and proposing that everyone accept it at face value because you think the one that was used "doesn't make sense", but in order for us to accept you as competent to rule on this, we need to see what your skills and experience are.
Once again - what was done is a matter of public record. It's not a matter of merely someone "saying so" - there's an unbroken narrative with supporting evidence in multiple forms, along with numerous third-party confirmations, during and after the missions.
Here's a broad overview of requirements, from a press briefing of the time;
"The NASA/Grumman Apollo Lunar Module (LM) after descending to the lunar surface from lunar orbit, provides a base from which the astronauts explore the landing site and enables the astronauts to take off from the lunar surface to rendezvous and dock with the orbiting Command and Service Modules (CSM).
The ascent stage is designed to:
Provide a controlled environment for the two
astronauts while separated from the CSM.
Provide required visibility for lunar landing,
stay, and ascent; and for rendezvous and docking
with the CM.
Provide for astronaut and equipment transfer
between the LM and CM and between the LM
and the lunar surface.
Protect the astronauts and the equipment from
micrometeoroid penetration.
The descent stage is the unmanned portion of the LM; it represents approximately two-thirds of the weight of the LM at the earth-launch phase. This is because the descent engine is larger than the ascent engine and it requires a much larger propellant
load. Additionally, its larger proportion weight results from necessity of the descent stage to:
(1) Support the entire ascent stage.
(2) Provide for attachment of the landing gear.
(3) Support the complete LM in the SLA.
(4) Provide structure to support the scientific and communications equipment to be used on the lunar surface.
(5) Act as the launching platform of the ascent stage.
= =
How does your design spec cope with, for instance, micrometeoroid penetration, or providing sufficient power for a descent engine, as well as allowing later takeoff for rendezvous?