Each year as Apple's World Wide Developer Conference (WWDC) approaches, I start to think about upgrading macOS to the version that was released at WWDC the previous year. I reckon that's a good way of minimising your pain and suffering, not to mention giving developers a chance to patch things that got broken when the API goal-posts moved.
The end of May 2025 was when I decided to upgrade both a 2019-era Intel iMac and an Apple M2 MacBook from Sonoma 14.7.1 to Sequoia 15.5.
Aside from the seven fractions of eternity that macOS updates seem to demand these days, it all seemed to go swimmingly. The only explicit grizzle was from Carbon Copy Cloner, which wanted a later version (on my to-do list).