I don’t think those reasons help at all, but I also feel that they’re not the underlying problem. I suspect that at the end of the day, the responsibility that comes with tanking is simply a turn-off to most. It’s like being the goalie in football. Who the heck wants to be the guy who watches everyone else run around, and gets blamed if the enemy team scores? There are some folk who enjoy it, but most people don’t sign up for that.
Back in late 2019, the devs reached the conclusion that they simply weren’t going to be able to make tanking more appealing and decided to cut down on the number of tanks needed to start a game going. This was before solo tanking was the standard, so that’s not the reason for tank shortages. There were also around double the number of support players at the time despite having a slightly smaller roster than tanks, so roster size isn’t the cause, either.