I had to look up how much Bjornsson weighs: 425 lbs.
Here's Cailer Woolam at last year's Slingshot Record Breakers powerlifting meet.
Woolam pulled 953 lbs at 215 lb. bodyweight. He uses a hook grip. No straps.
This got longer than I intended. TL;DR - I really like powerlifting and strongman.
Powerlifting =/= strongman
Powerlifting varies a but by federation, but you don't get straps and you can't have the weight move down at any point in the lift.
In strongman, you're allowed to use straps and you can "hitch" the weight up.
Both may allow knee sleeves or wraps, weight belts, and other specialty clothing (bench shirts, squat briefs/suits, deadlift suits) depending on the competition.
Squatting and deadlifting barefoot is actually better for your feet if you're lifting heavy because the cushion of typical gym shoes makes your foot less stable. Plus no soles reduces the distance you need to lift the weight by up to an inch.
The straps that Thor used were figure eight straps, which are designed to let the bar hang in your fingers rather than be up in your palms. Just like being barefoot, that reduces the distance the weight has to move and let's you start a little more upright.
At the end of the day it's World's Ultimate Strongman, not World's Ultimate Strongman Pound-for-Pound. Both lifts are super impressive.
It sounds like Thor and Eddie Hall (previous record holder and generally obnoxious guy) have signed a 7-figure contract for some kind of fight. Eddie was claiming that the record shouldn't count because it wasn't in competition. Thor previously claimed he should have won World's Strongest Man over Eddie in 2017 because the judge cheated him out of a rep. All I know is watching this fight will be like two big bulls squaring off.
Since World's Ultimate Strongman decides they would allow records to be set in personal gyms, there are a whole series of record attempts being made this spring/summer.