I'd guess that many people that are healthy and functional now have a good chance of making it, if they take care of their health and keep up with the latest research.

There's so much new information and science coming out every year, that help us make educated guesses on the best supplements and life habits to slow down aging greatly. And this is all pre-agi. For example, the evidence is currently very strong that regularly donating plasma is likely to greatly slow down aging because it helps detoxify the blood. Then you have senolytics, MTOR inhibitors, etc.

One thing that's important to note, is that LEV for those who keep up with the research and know enough about the field to weed out most pseudoscience/bad products, is not the same LEV for those who wait for things to be proven beyond a doubt, which is not the same as LEV for those who wait until all the treatments are popular enough that most people are doing them, and know about them.

LEV may even be different depending on your biological age. If you've biologically aged too much, then interventions may have a smaller effect than say if you started when you're 20 because damage to one system causes damage to other systems that are interconnected to it, so the less damage/information loss/junk you let build up inside you, the better.