Interesting. I've been using Gitlens for years without issue. Today I tried the built-in blame decorations and I found they were so responsive and fast that they were distracting. With Gitlens there's a delay before the decoration appears on a line, so if you're moving your cursor quickly around between lines you don't actually get a blame decoration until you've rested there for a few seconds; with the built-in functionality it pops right up as soon as the line focuses so if you go from line to line, there's a lot of activity in your field of view which makes it harder for me to concentrate on the code.

As an adjustment, for now, I'm sticking with the built-in functionality but enabling only the status bar display, whose template I modified to include the commit message and date.