I just dealt with this crap storm of a project last month. We had 40k photos scattered across three laptops, old hard drives, and sd cards. First I just crudely copied all of the folders on to an external hard drive and ran a freeware duplicate remover to clean out about 20% of them. Then I used a python script to go through this giant pile of pics and copy them in to folders by year and month based on the created date. It also added yyyy-mm-dd to the beginning of each file name. Now we are slowly going through month by month and adding simple tags in the file name (event, location, names). It’s far from perfect, but I didn’t want to deal with keeping everything synced in a database or locked in to a certain OS or app, plus it should still be searchable in 15 years when we are all running Windows 30 and Mac OS Ozarks or whatever.