The gen 5 should be the most durable on paper with the compressed coil springs that replace the breakage prone springs in the older Glocks.

I prefer the Gen4. That is when I really got into glocks. I had a gen3 g19 and it was just, meh. I also had a gen3 20SF, WAY different from the standard G20. Funny how 3mm could make it feel like a totally different gun.
I currently have a gen3 G30s, and I am ambivalent about it. It conceals nicely and is a lot of firepower in a small package. But I just don’t feel like I ever have a good grip on it.
The adoption of the SF measurements as standard on the gen4 was a big selling point to me on the large frame glocks.
The finger grooves never bothered me, I could take them or leave them.
I was mostly into large frame Gen4 glocks, 10mm & 45.
Then it was LEO trade in g22’s & g23’s.
I do have a gen5 G19, and the biggest difference to me is the beveling of the muzzle end of the slide. But I would be just as happy with a gen4 g19.
My gen4 g17 is nice as well.
I like the front serrations on it. Not a deal breaker either way, but it’s like a rail, it gives options.