Maybe everybody does this, but...

Heavy curtains, rail about 100mm from wall so lots of leverage.

Over the years, two brackets at one end have failed a couple of times
and have been fixed by using larger plugs. This time, the holes are
just too big. It's crumbly mortar and plaster which is the problem.
Unfortunate as the other five brackets are nice and solid in brick.

So, I hoover out the 10-15mm crumbly holes, squirt in some hot melt
glue, position a new rawlplug, then fill around it as best I can with
more hot melt glue. Trim excess and refit brackets.

Solid as a rock.

Cheers
--
Clive