I have had the same mobile phone number since 1990. Finally, I learned the number off by heart a few years ago (previously if anyone asked me my number I'd have to open up my contacts and look for "me" to read them my number). Nothing has ever happened that would make me change the number and I'd rather endure a campaign of unsolicited or malicious calls than change it.
We all make our own choices in how we conduct our punting business but surely there's no need to change a punting SIM until there is a latent and pressing problem...... It could be tomorrow or 10 years. Just changing it as a "precaution" every say, six months seems excessive, pointless and futile