Analog film photography and cameras

What level of automated "improvement" occurs in modern-day film processing?
Back in the 90's when I used to send my films off to Jessop (GB) or HL Markt (D) I'd expect about 20% failure rate . nowadays everything I send to Snaps photo services is bang-on.
I'm a bit more sober these days but even so, the majority is still sunny 16-guesswork on battered old cameras so I can't be that much improved over my 15 year digital hiatus (2000-15), particularly in view of my deteriorating eyesight...
I'm assuming that modern day machinery automatically pushes underexposed images to make them nice - is that likely or would you need to push the entire film?
Maybe it's just the scanners that improve everything - the metadata tells me it's a Fuji SP-3000, presumably that's where the magic takes place....

My experience has actually been the other way around. The shots i took 10 years ago seem to be a lot more contrasty and had better colors then what i get lately. But that might just be because these days film sits forever in my camera's.