I know a lot of people who live many years with a single pair of:
ESL57, Spendor Classics (sp100, 2/3, 1/2), Harbeth, Magneplan, Klipsh, old Tannoy, old JBL L200, Altec (A7, 19 Valencia, 604, 605).
I listened to my B&W Matrix 801 S3 for 21 years, and I was consistently impressed by how good they sounded. Of course these speakers were mainstream recording/mixing monitors for a similar length of time (maybe longer).
This model was before all these dummy diamond tweeters.
But modern B&W went far away to more modern audiophile stile of sound.
And I think it is nothing wrong to exchange your speakers every year so far you enjoy to do it.