Wiping on a sealer is hardly a major project. I have never used 20 years......if my clients won't be dead by then , I may be : ) in which case I assume they will not haunt me for issues I can do little about.

I stick with my fabricators recommendations for every six months or so. Nobody listens to that either, but only so much hand holding I can do, right?

The sealer would be applied by the granite fabricator, not at home.

When you dribble water on your top and it doesn't dance like water on a freshly waxed car, it's time to reseal. A pint of Tenax Proseal would reseal a 75 sf countertop on site every year for decade probably and take 10 minutes each time.