I'd still play it, but the overall experience would certainly be lacking. The longevity would be lost. Like you, my history with the series is quite similar. When I first played PES on the PS2 I was
so enamored with how different the gameplay was compared to FIFA I couldn't have cared less about the lack licenses. The editor was sufficient, I tweaked the Manchester United squad to the best of my ability and that was enough to satisfy a 12/13-year-old me. Ever since I got a taste for modding with PES 5/6 that's changed entirely.
To be honest I
love minor details in games, especially football games since it's based on real life. I want to see what I see in real life, in PES. Proper adboards, banners, stadiums, kits, faces, hairstyles, nets,
everything. It really adds to my experience. Hell, I'll edit the sleeve length (likes of Vidic, Carrick, Giggs wear short sleeves during the winter) of every United player so they properly reflect their real-life counterparts.
I've said it once, I'll say it a million times; Thank God for PC gaming and their respective modding communities. To all of those who help enhance our games beyond their vanilla state, I salute you.