Year 1: The surface looks a little dull. A bit of algae starts at the edges where the lawn meets the concrete. Easily fixed at this point — a single wash brings it back to new.
Year 2: Mold and mildew have established colonies in the pores of the concrete. The grey-green tint you're seeing isn't going to leave on its own, and rainwater is now feeding it instead of cleaning it.
Tired of looking at a dirty driveway?
Get a Free Pressure Wash QuoteYear 3: The HOA notice arrives. You now have 14 days to remediate what three years built up. The clock is loud.
Year 5+: Biological growth has been holding moisture against the surface for years. This accelerates concrete degradation, and on pavers it displaces the polymeric sand between the joints — which causes shifting and unevenness. Restoration at this stage costs significantly more than a decade of regular maintenance would have.
In South Florida the timeline is compressed because of the climate. What takes three years in a dry state can happen in 18 months here. The cheapest version of this is the boring one: clean it twice a year and forget about it.