IMO there's an often unspoken divide here.
There's the group of people for whom doing these "Algos I" problems in university was relatively painless; not that all problems were "easy" but there's an ease to approaching the problem, and with enough continuous effort the problem is solved. These people also tend to have good retention such that 10 years later, they just need to practice LC for a few weeks and they're back in top form, even if they've been building the easiest CRUD apps for years and not working their brains at all. I've seen this firsthand.
There's another group of people who, for whatever reason, are lacking the facilities to calmly and clearly approach these problems. Doing "Algos I" was a serious grind, and the Brain Toolbox for solving these problems falls apart quickly once the final has been taken. Even if doing relatively complex work at their jobs for years, when it's time to practice LC, it may take months to get anywhere near "top form".
Obviously everyone is on a spectrum between and beyond these two groups, and I fall closer to the latter.
Now add on the fact that there's a person watching you who is going to dictate whether you get a paycheck at all or a 20% boost in income. Or you're like me right now and you've been laid off. Now add on that you need to do it in 20 minutes, each minor mistake potentially becoming a devastating error if you don't catch it quickly.
I envy anyone who can just focus on the problem and remove all surrounding context. Still trying to figure out how I can add stress distractions while timing myself.