Q: Photos - why make a good thing bad

Get iPhoto 9.6.1 if you didn't update before OS... | Apple Support Communities

Open your application folder and use iPhoto if you had the latest version of 9.6.1.

You do not need to "get it back" - it is in your applications folder - use it until a future OS upgrade breaks it

LN

Apple is creating a platform where the software on its hardware will be the same across devices - and photos working with Icloud seems to be a geared towards synchronizing your digital pictures taken with ipad or iphone onto your mac. 

Have you looked at the following support pages

iphoto getting started

https://support.apple.com/en-us/HT204655

https://support.apple.com/en-us/HT204410

https://support.apple.com/en-us/HT204264

https://support.apple.com/en-us/HT204414

Thank goodness - I whole heartedly agree with Marianne.  The moment I opened iPhoto, I gave a big sigh of relief (thanks for showing me that the app wasn't lost forever).  For me, the speed is the issue.  iPhoto wasn't perfect, but I could run right through 50 pix and identify through Face Recognition rather swiftly.  But, in Photo, it could take up to 8-10 minutes to ID One (1) photo ... yes... that long.   I don't know what degraded the performance with Photo ... but, if it doesn't get fixed, I'll keep using iPhoto until it doesn't work anymore.  Thanks for the tip.