The loft of my badger hair brush has shortened

Now that is a well loved brush! However, its lathering days are over. You definitely got the most out of it.

What could I have done to prevent this from happening?

What could I have done to prevent this from happening?

5 1/2 years on a brush.  That's about 2000 shaves.  From the picture, others are right.  This brush is worn out.  Best practice to extend the life of a brush is to not splay it more than about half way down the fibers.  That said, some guys would rather have a heavy face-feel than brush longevity.  In that case, continue your style and buy a new brush every 5 years.  Synthetic fibers will last longer and more than one brush will allow complete drying between uses.

Maybe the result of soft, succulent, luxurious bleached tips and 'tend to push the brush hard'.  Just a guess.

+1

I’d reknot with a synthetic.

+1

Some strong synth, with a huge density.
Maybe a Black Boss, or similar.

I would suggest to buy a few brushes and to put them into rotation. Don’t mash down on the knot.

Yep, if you are going to stick with badger, get several. Enough that they can dry completely before reuse, 3-4 days.

25% max shaft flex is a good rule of thumb. Swirl or paint, just dont bend the shaft more than 1/4 its length when loading or lathering.

22x50 sounds like it would have been kinda floppy to begin with, which required more pressure to work, which eventually killed your brush.

If the soaps you use are hard, a floppy brush will take a beating trying to load it. Consider measure to soften the soap a little.

I've not used a 22mm badger...but I do face lather and would question whether a 22 would hold enough lather for 3+ passes. I've got a 26mm, several 28s, and a 30mm. All build lather like mad and hold plenty.

If you only want 1 or 2 brushes...or if you are gonna mash them hard and run them wet...get synthetic knots. They will tolerate the abuse....even if the dont, they are relatively cheap.