It wasn't perfect in previous versions - what's new is that files are getting bigger. Yes, this bugs me too, but only since I regularly started working on 7000-15000 pixel images.
It's just a logarithmic scale, it goes up fast at large sizes. Obviously the assumption is that the larger sizes are very rarely needed.
I totally agree, it's time to re-evaluate the scaling.
It was perfect on previous versions. Any way to change it back?
It has worked the way you describe for a long time (I just tested as far back as Photoshop CS4). The maximum size has been increased in recent years, which may make the last part of the slider seem even more touchy.
Have you tried the new on-screen "hold down the Alt key, right-click, and scrub" method of brush resizing?
You might try using the scrubby slider instead of moving the actual slider for the brush size.
Hold the mouse over the word Size and you'll see the cursor change to hand with arrows, then click and drag left or right.
Include the Shift key for faster or the Alt key for slower
Of course, what Noel suggests works very well