“Councillors at large” are the bane of any system they’re in: they float in the background beholden to none of the voters,
This is FUD. An open-list MMP system has nobody whose name was not on a ballot - the idea is that the backfill-seats go to the most popular people (by ballots) within the backfilling party. So if there's some loathed backbencher within a party, they can't squeeze in by the list because voters who like that party can still vote for somebody else.
And STV is even more direct in that every person on the ballot is ranked individually by voters, it's just STV includes multiple members of the same party on the same ballot because there's more than 1 seat up for grabs in the riding.
We have parachute MP candidates today. We have PCPO candidates who don't even show up for debates. Jack Layton managed to get Brosseau a seat in Quebec, when was a college student who spent the election in Vegas and didn't speak French. I doubt half of Canadian voters could even name their current MP.
Celebrating an absurdly disproportionate system in order to preserve something that is already a sham and with attacks that aren't even relevant to the systems on the table is ridiculous. nobody is proposing a closed-list system.
Many countries have switched from FPTP systems to proportional systems. Many more have campaigns to do so. How many countries have the reverse? How many campaigns are out there to go back to FPTP? None, because it's a dumb system.