I’m close to 50, been running for decades, and still pull over 2k miles annually. Almost all that on asphalt. Haven’t experienced any joint problems yet. I credit three things for that. First, modern running shoes are designed to soften the impact, and recently they have gotten ridiculously soft. The extreme cases give you 50mm (about 2 inches) of soft foam under your feet, but even more normal running shoes have advanced foam and bouncy elements in the outsole to soften the impact. Second, proper running form is not rocket science, and most people fall into a decent running form naturally. This form is the most gentle on the joints. And finally, if you are serious enough about running to go the distance where hard surfaces could be a problem, you are already likely to supplement your running with strength training, which further helps to protect your joints.