As long as people will be eating meat, leather will always be a side product. The negative environmental effect would be far worse, if leather was not further processed. Processing leather in approved tanneries is definitely a more ecological option. The demand for animal products keeps growing, and so is the amount of leather. The natural degradation of genuine leather is also not a problem for our environment. On the other hand, materials made of PU, PVC, PE can take 200 – 500 years to degrade completely. The ability to recycle is also often debatable.
Another downside of imitation leather is that most of it is made in south-east Asia – China, India – where the processes are unecological, childhood labour is often misused and products are delivered on cargo-ships, which are the largest polluters of the oceans.
Our own experiences with imitation leather were unpleasant. Just delivered, brand new imitation leather had a strong chemical scent, which caused us headaches for couple of days.
Everybody can make their own opinion about what is a better ecological option.