Campanula pyramidalis question

Jacquimcmahon

Morning everyone. I have a few campanula plants dotted around in pots, one of which seems particularly happy. Loads of lush growth and at least 10 main spurs. 

I was looking up whether or not it was a good idea to split it or thin it out, then everything I read said it was “a relatively short lived perennial, best grown from seed each year…..” mine has now been going for 4 years….. is this then unusual?  What exactly is the “relatively” here? Thanks for your thoughts.

Pete.8

I sowed seed a couple of years ago and planted about 10-12 out the following spring.
They flowered beautifully last year, but I can see only one that has returned this year.
Lovely plants and I will be sowing more this year