OP is all over the place on this thread but I reckon it boils down to this:
OP is going for the last line of defence:
Use the offer of resignation to introduce false equivalence.
The situations are not equivalent:
Boris Johnson misled Parliament about holding social gatherings during lockdown.
It has been proven that these were social gatherings.
He was - and still is - Prime Minister.
He was responsible for the laws he broke.
He misled Parliament.
So now we have a Leader of the Opposition offering his resignation if found guilty of lawbreaking.
The Leader of the Opposition is not Prime Minister.
The Leader of the Opposition did not mislead Parliament.
It will be found to have been a work-related break.
(Despite the fact the OP asserts it wasn't, the proof seems to already exist, so ...)
Misleading Parliament has never been an issue.
We will be left with Johnson continuing as Prime Minister, despite having been found guilty of having broken the law he was responsible for, having misled Parliament, having dragged down the public office he is entrusted with.
All thrown into relief by the Leader of the Opposition having behaved with integrity.
The only thing those who wish to save Johnson are left with is to try and use this to minimise and normalise what Johnson is actually, really guilty of.
That is, try and claim there is an equivalence between Starmer's work team having a food break at 10 (yes, that is how it goes when campaigning) & Johnson having a series of jollies & misleading Parliament.
It's desperate stuff.
There is no equivalence.
Johnson is a shit, basically.
Johnson thinks being Prime Minister is a big joke.
He does not deserve to be PM - only the turbulent politics of the last six years could have put someone so wholly unfit into office.
He doesn't deserve these efforts to 'save' him.
Every minute he stays in post is a minute we (people who think that politicians have a duty to treat the responsibilities of office with respect) are being laughed at.
He should go.
He should resign.
Starmer is offering to resign.
He won't be found guilty.
He won't resign.
Johnson should resign.
He has been found guilty.
It has happened. He should go. He won't go.
The focus on the drama about what might (but won't ...) happen with Starmer distracts us from the fact that Johnson is still there as our Prime Minister - and he is wholly unfit for this role.