Why did Apple discontinue iTunes without replacing it with a functional alternative?

Why did Apple discontinue iTunes without replacing it with a functional alternative? What options do I have to play them anymore? Is there a future for playing my Apple-purchased media, or have they given-up on me/us?

I have 740+ movies, a myriad of TV Series, Music etc on iTunes, but none of my Apple devices: iPhones, Desktop Macs, iPads & Apple TVs, play my Apple-purchased media.

• The ability to search my own purchased library is broken
• TV (Apples new-ish app) doesn't fully play any Apple TV+ all the way through
• The TV app/program is unstable on most of my devices, including my new iPhone 12 Pro Max 5G
• The TV app/program is a resource hog and can bring my Mac Pro to it's knees

HELP! Most of us love you, but you've left us stranded!