I have a 11 pro max only 5 months only am using but my battery health now 96

Battery will tear & wear anyway, because of the chemistry, usage and time.

Tips that will make your battery last longer are:

• use authentic charging accessories
• do not allow overheating
• do not play games while charging the battery
• do not let it discharge to 0%

Put it on a charger at 20-10%, use authentic or Apple Certified accessories like cables and power adaptors and you'll be good.

That's normal.