Basically your ***''battery is dead''*** and needs to be replaced. I had the same issue with my Beats X in-ear headphones.
My Beats X were also 5 years old and I hadn't used them in more than six months, which probably made things worse and allowed the Li-ion battery to discharge completely.
I tried these options before confirming the battery was dead and needed to be replaced:
# I charged my Beats X overnight for more than 12 hours.
# I attempted a ***''factory hard reset''*** by plugging in the lightning cable to the charging port and then holding down the power button + volume down button at the same time, for 10 seconds or longer.
There was NO LED flashing after the factory reset. I removed the lightning charging cable and holding down the power button didn't start up my Beats X. After plugging in the lightning charging cable, the LED would flash white/ red/ white/ red and then stay on white.
***Helpful Resources & Guides:***
* This [link|https://youtu.be/zg9k4c1WeRk?si=Xt_MGG_Df2N2RoyP|brilliant guy in San Francisco|new_window=true] produced a superb video on how to replace the original Beats X 50mA Li-ion battery A1773.
* This [link|https://www.joesge.com/blogs/beats-ear-bud-repair-guides/how-to-replace-the-battery-in-beats-x-wireless-earbuds|place|new_window=true] sells new aftermarket ***replacement batteries(***[link|https://www.joesge.com/products/beats-by-dre-beats-x-wireless-repair-parts?variant=31472692461614|$14.49 each|new_window=true]***)***; and offers a good written replacement guide.
***''I hope this helps!''***