What about all the people who cannot get to the polling station?
In days of old, people had to declare they was in a demographic (elderly, disabled etc) that couldn't get to the polling station.
These days anyone can ask for a postal vote and that's very bad, especially since there are no safeguards against voter coehercion.
If the voter has the secret vote at the polling station, they are near impossible to coerce because bad actors have no way of knowing whether the victim voted the right way.
Now imagine I live in a house with 4 other people and I am the head of the house with control over who can stay in it. Every now and then, the local authority does it's own canvass.
There is only ONE piece of paperwork for that, that lands on the doormat. I add in anyone who lives with me, that isn't added in on that paperwork and everyone get's the tickbox for a postal vote.
Then all I have to do, is tell everyone in that household, that they are voting by postal vote or they are OUT.
The local authority may phone them, asking them if they want a postal vote. They will simply say they do, otherwise they are OUT of my house.
I have them, right from the word go, from the start, to the vote the day the ballots land, to handing over the ballots to the party I want them to vote for.
The system is shit shit shit shit. Oh and bit more shit. It's wide open to abuse. But that's OK according to some here, because there's no election observers in my household to record wrong-doing so it never happened!